SADDLING
To saddle ours, using our user-friendly equipment:
1. Take the lexan-aluminum packframe, snap on the pad and all rigging as shown.  (by 'rigging' we mean all the straps that hold it in place on the llama: a chest strap, a crupper or breeching that goes in the back, and two cinch straps which pass under the belly.)  Each set of rigging will be adjusted to the right size for one of the llamas on the trip and marked; taking the time to check that the sets go together and get on the right animal will save you trouble.
2. Tie the llama short to some tree or post.  Most of ours, most days, don't need this, but you can't depend on all of the llamas to stand still all of the time, especially if their wool gets stuck in the attchments.  brush off any pine needles or deris that has accumulated on the saddling area.  Packsaddles can be put on from the right or left sides, the llamas don't care.
3. Spreading the springy bows, place over the llama's back behind the shoulder blades.  (To be sure you know where these are, place your hand about a foot back from the chest about halfway up the torso and get him to take a step.  You will feel the scapula bone move.  Keep the saddle bow behind that spot, it'll make him sore. The pad is OK here.)  You don't want it so far back that most of the weight is on the kidneys.  To make this easy for our customers, we clip the wool in the right spot.
4. Now reach underneath the llama for the front cinch strap.  Make sure that they are not crossed and that the padded area is centered under the llama.  Now bring it up and slip it through the roller buckle.  You want the saddle to be tight enough that it will not slide around, but not to restrict breathing or cause discomfort.  Tighten the cinches to about the same tension you would want on your boot laces.   Do the same for the second cinch strap.
5. Next, bring the chest strap across the front and snap it to the lower lash point on the opposite side.  Presumably, this is the correct strap and has been pre-set for this llama.  If it is too loose or too tight, adjust it evenly by the buckles on both sides.   Clip the center ring to the collar to prevent sagging.
6. Last comes the breeching, which is not the llama's favorite part.   Using the supplied cleaners, oil  the round leather part which goes under the tail.  Snap it to both sides first, then lift the tail and slip the strap underneath.  Adjust so that the pads rest against the pelvic bones and the crupper is centered under the tail.
7. Check the saddle to make sure that it is centered, secure, and not too loose or too tight (remember the boot laces).   Often there are 'paths' in the llama's wool that show where the straps should go.
8.  Have a helper stand on one side with one pannier while you are ready with the other.  Place both loads on at nearly the same time, trying not to let one weight hang unbalanced as it may drag the saddle to that side.
about our saddles
We have custom-designed saddles for our llamas since we started packing with our first in 1982.   At that time, there was no llama packsaddle available.  We started with an awful padded leather contraption with a single nylon webbing cinch and fore-and-aft D-rings for tying on the load.  From this we went through a variety of home-made, new and used varieties as they became available: soft packs, crossbucks, injection molded re-worked saddle-trees, oak-and-brass slatted heavyweights, adjustable steel-tubing affairs, and the like.  We fastened them on with single cinches, double cinches, chest straps, breeching, cruppers, with various straps to hold all the latter where they were supposed to be and keep them from sliding to inconvenient, painful or non-functional positions on the llama's anatomy.
the problem
Almost all of the systems were fine for short dayhikes on easy trails, once you got the hang of how they fastened on.  But when novices had to get them on correctly, or the llama you were packing wasn't the same size and shape as the one the manufacturer had used, the animals got saddle sores from the ill- fitting equipment, which didn't add to their enjoyment of the mountains.   Without horizontal rigging, every single saddle we tried slid around when the terrain got difficult, with steep ups and downs, or half-melted snowbanks the llamas could fall into without notice; or when cross country rockhopping and bush-whacking was called for; or when the load was a single overstuffed frame backpack belonging to a hiker with heat exhaustion we met on the way out ---  well, we found that the saddles we had could use a lot of improvement.  What we needed was:
1. tack and rigging adjustable to fit a range of llamas without binding, chafing or slipping;
2. a saddle that would stay in place uphill and down, through jumps, twists, and things knocking on the load;
3. something that a relatively inexperienced person couldn't miss gettng on in the correct position
 4. fastenings that worked quickly, easily, didn't catch wool, and gave leverage where needed;
4. attachments which could manage bulky soft panniers, rigid boxes, and posts / shovels for trail work; and
5. a unit that was light, useful in camp, weatherproof, and could withstand reasonable wear-and-tear.
So we set out to make it ourselves (we wish we could add 'ease of manufacture and inexpensive components' but you can't have everything.)
the frame
Our current version has a covered foam pad which fastens to the saddle to hold it securely in place during use, but is detachable for sitting on when in camp.   (Put 2 together to make a 3/4 sleeping pad.)  Front and back caliper-shaped polycarbonate 'bows' give the saddle the stiffness of a frame while retaining some of the flexibility of a soft pack.  Each 2' wide strip of polycarbonate has to be custom-molded and pre-drilled (a difficult and expensive process), then the tops are bolted together with steel loops to which loads may be snapped, tied, bungeed, or over which pannier straps can be cinched, depending on what is being loaded.
cinches
At the bottom of each bow on both sides are large buckles for the two cinches.  We are currently using belt-grade latigo leather cinches with felt pads connected at the bottom.  To make cinching up even simpler, the buckles are the roller-type for good leverage and the pad extends below the buckle so that the wool cannot get wrapped in the buckle when tightening.
chest strap
The two bows are spaced 14' apart (narrow enough to keep the load off the llama's shoulder blades) by two inch-and-a-half aluminum crossbars, each terminating in fore-and-aft D-rings.  The upper set of rings are extra lash-points for the load, while the lower set of rings are used to snap on the horizontal rigging. We use an adjustable padded chest strap with a center ring which can be clipped to the collar to prevent sagging.   With this reinforcement, you can add a small chest pack for holding loads under 5 lbs., like a water bottle.
breeching/crupper
In the rear, we use a draft-horse-sized crupper with conway buckle adjustments, which on a llama opens out to make a very nice semi-breeching.   We thread the strap through a pad on each side which puts the pressure against the pelvic bone where it does not hamper hind-leg motion; this also serves to keep the adjusting buckles from rubbing.  The inch-thick stitched leather roll is stuffed into a U-shape shaped and tends to ride right under the root of the tail, which our llamas are now used to and comfortable with.  (Warning: the llama won't like it the first time --- they don't like you messing around that close to their testicles.)  Sometimes if a loose crupper tends to sag too low when it gets loose on the uphills we will put a strap over the back snapped to the adjusting buckles; clipping a 'path' in the wool also helps keep straps in place.