If you are making your own calls, you just have to experiment until you find what will work best for you. There are so many different variables in mouth call use that there is no one-size-fits-all call design. My advice is to get enough material,....call frames (of different sizes), tapes (that fit the call frames), and an assortment of latex thicknesses and colors,...to make lots of calls, and then start experimenting until you hit the combinations that you are best able to replicate turkey sounds with.
Typically, combining different latex thicknesses and reed spacing and cuts will begin to lead you where you want to go with your mouth calls. To get an idea of reed spacing and cuts, you can just take a look at any turkey hunting catalogue and look at the calls. If that is too confusing, just remember that a lot of calls start with a standard center V-cut design in the primary sound reed (upper, long reed) and then vary from there. You can't go wrong with starting with the V-cut and then modifying from there until you reach the sound you want.
Since the upper long reed is the primary sound reed of a call, you can use varying thicknesses of latex, including prophylactic, as the upper reed and after making some calls, you will begin to understand how the reed thicknesses, layering, and cuts effect the sound of the call.
Many mouth call users make the mistake of discarding a call that does not sound the way they want. Any mouth call can be modified by making additional cuts in the reeds,...primarily in the long reed, but also in the secondary reeds (although cutting the secondary reeds often will deaden the sound of a call, but not always).
The best thing to do with any call that does not sound the way you want it to, including those purchased from any call maker, is to modify the reed cuts. The sound of all mouth calls can be modified, and often made to sound more to your liking, just by making some very small changes in the reed cuts.
Finally, don't get hung up on trying to make calls that sound like the very best contest callers. Calling turkeys does not require that you are good enough to compete with those guys. If you listen to real, live turkeys, they can vary greatly in the way they sound,...and most rarely sound like a human contest caller. If you stumble onto a call design which allows you to excel at calling, more power to you, but impressing real turkeys with your calling is much easier than impressing contest judges.
