I use the old sandbags for sighting and checking a hunting rifle.
These 1000 yard shooters around here have these elaboate rails that they mount to but, then they are putting 10 rounds in a 10" or smaller target at that range.
If you're lucky enough to be on private land and can leave your stand up during the off season you can tie an old piece of cloth or something of the sort to your stand. I like to use an old camo bandana that I have. That way the deer get used to the movement and eventually don't bother even looking up when there is slight movement. This may just give you the time to draw your bow or raise your gun without being detected.