I don't have much experience with venison, but I am very successful at making top round london broil more tender than filet mignon. I use the following techniques:
1.) Take your steak, throw it on a cutting board and beat it with a "bumpy" meat tenderizing mallet until it's roughly half the thickness.
2.) Salt and pepper the steak and allow it to sit in the fridge at least overnight, preferably 24 hours.
3.) This is the most important part: allow the meat to sit out and come to room temperature before cooking. Throwing a cold steak in a hot pan results in shoe leather. This usually takes around 2 hours or so for a reasonably sized steak.
Other options are to marinate it overnight in tamari if you want less meat flavor. This works great with Asian stir-fry's. I've had great success making $2.50/lb meat taste like $12.50/lb meat this way.
Don't put your trust in anyone on this forum, including me. You are the key to your own success.