Take a srtinger along with you. IF the bow has a viable string, string it up, hold one tip in hand put other tip on ground, rock it back and forth and see if the string is centered. Does the string line up with string grove below the tips if it has these. This will help with limb twist. Look for cracks and splits along the edges of the limbs, look for discoloration in the glass on the limbs, any bubbles, delamiantions, lots to look for but there are a lot of good bows out there that will last for years while other will fall apart on yea ....