Matt,
I have tried G clamps to apply backings. It seemed slow, heavy, annoying etc.
I much prefer to wrap with a "bandage" of inner tube strip. I like to use a slow setting glue like resorcinol which gives plenty of time. Once wrapped you can leave th bow to set straight or clamp the middle down to a board and lift the tips to give reflex, or put the handle on a block, pull mid limbs down to the board and lift the tips up onto blocks to give reflex deflex. It's a very simple method and doesn't need jigs.