A postal scale, a dietary scale, or a scale app on your smart phone, in that order.
Its tough to guess weight on a chunk, but easier on chips if you're doing a short dense smoke, like cold smoke for cheese. By my scale, a ziplock snack bag with the bottom covered all across, such that, when rolled, I can get my index finger and thumb around it without squeezing. If you gots ham hands or piano fingers, YMMV.....
I believe in catch and release fishing. I don't want to EAT 'em all, I just want to GREET 'em all!