for my front i use the ones seen in the attached image. wide variety of colors and kinds. have been stashing my equipment in the front regularly in one of these
The standard Adrenalin one works good. Wear the helmet, leave bulky shin pads at home and have the straps done up to the point just before the top of the bag hits your chin..
I used to wear my stash bag on the front on a few different objects especially cranes but mainly just gear up before climbing now. As I would climb, my knees would hit the bottom of the bag and knock it off my shoulders so part way up the section the bag straps would be at my elbows. Also when leaning forward while crawling through various small holes the bag would inevitably slide off. They need another strap to keep them close to your body.
Has anyone considered using a piece of 550 cord, or even an extra long static line, with a carabiner on both ends and clipping it to your belt? If you wanted to get really fancy, you could make something like this/out of this: