They're going to have a different rack the next year so you can't go by that.
In many cases, the characteristics of a deer's antlers will repeat themselves amazingly accurately from year to year. Of course there will be changes as a buck matures or gets past its prime, such as more points, longer tines, etc. But similarities will include width, relative lengths of adjacent tines, blading, split tines, type of beading on the antler bases, and even specific wiggles in a particular tine. Comparison ofsheds or photos from different years can, indeed, be another good tool to help identify different bucks, and possibly to determine age if you have enough antler history.
Here's a couple examples, although the similarities in characteristics are not blatant and a fairly close look is needed.
The antlers on the left are from the same buck, one in 2004 and the other in 2005. Notice that the main beam is quite straight from the base to the brow, the brow tines are quite slim and of similar length, and the G2's and G3's are very even on both.
The antlers on the right are from a buck in 2005 and 2006. The beams have a noticeable curve between the base and the brow, the brows are quite bladed (especially 2006, top antler), and the G2'sare shorter than the G3's (tip of G3 broken off in lower antler)
Note that the 'junk' at the bases increased on both deer in the latter year.
