First I try to avoid the object while applying breaks, if I can't and I'm about to hit, I apply the back break a tiny bit harder than the front (so I can still steer), I lift my backside off the saddle and position myself behind the seat (like mountain bikers do when going down a steep hill), to try to slow down the bike with my body weight and to also not be propelled, head first, over the handlebars of the bike.

If I cannot stop in time, I prepare to release the handlebars, jump off the BACK of the bike and land on my feet or butt. I'd rather my bike hit the object WITHOUT me on it than to either be forced head-first over the bars or crash into the object while on the bike.

I had a near-ditch situation once but I held onto the handlebars while landing on my feet, behind my bike. with the front wheel of the bike lifting up (my bike was completely vertical at that point). It saved me from having to hit a crazy ped that ran out into the bike lane between a large SUV and a delivery truck. The ped didn't even look. Ugh.

You should practice emergency stops in a safe place with a helmet (and any other protection like elbow, wrist and/or knee guards). A little practice could save your life.