Well placed game cameras can tell you what is moving through the area, and stands may allow you to get closer... On the smaller property it is unlikely that you have a stable resident deer population, and it is more likely that many of the deer you see there are moving from one property to another. On the larger property this may not be the case. If you don't have big deer the only way to get them is herd management. Have you considered forming a cooperative management strategy with the landowner and surrounding landowners? Without this, it is difficult to have a meaningful impact on the herd structure. For example, if you are the only one culling spikes you will not have an effect on the % of spikes in the herd. Likewise, (if you have the ability) culling does to improve the buck:doe ratio increases the benefit of any feeding strategies you employ- because a higher % of bucks get the high nutrient grub- and decreases the prolonged stress of mating season. It also really sucks to pass on a nice 2.5 year old 8pt only to know that your neighbor will shoot him on sight. And, feeding strategies have a greater benefit if they are widespread and sustained.
Game cameras, food plots, and supplemental feeders is where I would put my money- not necessarily in that order. I would invest my time in getting surrounding landowners on board with a herd improvement plan. If you can get enough landowners covering a large enough swath of land you may be able to enlist the State Fish and Wildlife Department for assistance in the form of management planning and potentially management tags. Here in Texas, landowners can apply for MLD permits to harvest does in excess of what they could via their licenses, and can harvest does in counties where shooting does is otherwise prohibited.