Where do you guys look when there is no big crops of acorns, soft mast, or crops? I have found that they love plant bulbs. Anything else you guys have found?
That is contingent on the ecological landscape you find yourself in. The short, easy answer is where pressure isn't. Assuming your hunting mature bucks, they'll travel miles to their primary food sources. That could be thick CRP cover, marshes, swamps, or even overlooked areas along roads / near parking areas. There is always natural browse depending on the time of the year, so don't feel tied to the ag fields.
In marshes and swamps, they hit red brush hard. I've also seen them hammer locust pods in river bottom terrain and some big woods settings as well.
Like Mledge said, there is always a preferred food source. We may or may not be able to readily identify it but it will be there. Also like he said honey locust pods if they are good can be spectacular. Other non-mast food sources that have paid off are bull nettle(that was a real bad year), honey suckle, dewberry, mulberry leaves when they drop, maple and oak sprouts on re-growth in a fresh cutover. If it is a really bad food year, it may be more productive to key on pinch points and funnels (not that there is ever a bad time to not key on these) than to burn the woods up looking for a scarce primary food source. To me it depends on the size of the place I am hunting, if smaller, I for sure would quickly key on topo features, if it's a real big chunk of ground, I may still look for those food keys as well.
When hunting back east on State Game land, I look for funnels and really in most states where I hunt whitetails. I normally hunt in tree stands in thick stuff. Snow really helps, if I can get it. When hunting pressure starts, bucks stay in cover. I normally don't hunt food sources or open areas back there, but that is in PA and in the mountains, where acorns and local grasses are the primary food source and could be anywhere. I really hunt off of hunting pressure. Texas is the exception. When hunting in Texas, the corn feeders make it relatively easy in some ways. When I hunted there I normally glass down wind from the feeders, when does are under it eating. I found bigger bucks hung back. Fields on the lease were also productive early and late. A lot of variables, depending on state, laws, public or private land, etc. Thats the fun of it. Strategery.