Big country, one of the beauties of this bow making thing is that several different designs can yield very similar results, for non reflex desings, elbs, holmgardes, piramids, and a million variations of these can produce very similar results. Number one most important thing for performance is dry wood!! You simply don't stand a chance with out it. I don't worry about it much on my everyday bows and just settle for whatever they come out as my moisture is just a little on the high side and still acceptable to me. I tend to favor the woods with higher oil content that seem less sensitive to moisture issues.
I think the other important thing is moderation in design, nothing too fancy, the more curves you put in a bow the wider you need to make the limb and the wider you make the limb the more it will vibrate and flop around. I had a guy build me a modern longbow this year for the flight shoots, he incorparated a lot of the simple tecniques we use on wood bows and the bow looks like it set a new speed record for modern bows hitting 202 fps with a 10 grain arrow at 28". he used a moderate r/d design with less than 2" net reflex.
I think another thing that is important, instead of glueing in 4" reflex to finish with 1", try glueing in 2" reflex and finishing with 1 1/2. The wood is a lot stiffer when it hasn't been damged so much, has less hystresis, higher early draw weight and stacks less. If you are tillering a bow out and it starts to show sings of loosing it's reflex at say 24" it will likley be a fast bow at 24" but not get much faster as the draw length increases unless you can get more wood involved in the bending process and stop the set from increasing. I try to start my bend in the mid inner limb area and as needed I work toward the handle and out toward the tip. I use a method of monitoring the wood that doesn't involve measuring the set. I use a bench mark of say 20" or whatever and check the draw weight there, as I draw the bow out further I keep going back to my bench marl to check and see if it has lost any weight. Every time I remove wood I have to establish a new benchmark. This is realy effective as the wood will actually start to drop in weight before you can visually see the set happening.
I am not really sure about the next statement I am going to make but I suspect that when there is a radical transition in the shape of the bow both in width and thickness it seem to interupt the harmonics somehow and lesson the distorsion or vibration on the return stroke. A holmegarde would be an example of this, I use a modified version of this on my outer limbs in the r/d designs. Steve