Apples, salt, COB, food plots, water tank are all good ideas.
However, it's important to not overestimate the results of a food plot or bait. Bucks will find and return to these offerings but if you're not making them very convenient to their established daily pattern, the deer will not be by too often.
.42 miles isn't a super long distance as far as muleys are concerned but I think the real results of a food plot won't be evident for a few years. Nothing like delayed gratification!