Every time I string my selfbows I take several warmup pulls to get the bow ' limbered up' . 1/4, 1/2, and 3/4 draw a couple times each before finally getting into a full pull. I really don' t know whether it helps or not, but I feel better for doing it.
I also unstring the bow several times a day during a hunt and let it rest; I never leave the bow strung overnight; I keep the wood sealed and dry (wax the snot out of it!); of course one NEVER stands a bow upright in a corner.
Someone like me that draws a selfbow some 31" will put some serious string follow in a bow that' s tillered for a 29" draw - if they don' t break it outright. Never let anyone draw your selfbow if their draw length is longer than yours. I don' t have that problem very often