Probably the biggest thing is to make sure you have power to the bilge pump. Boats at the dock don't usually get a huge leak - mostly a small one that drains the battery as the bilge pump cycles. If the bat drains because of a slow leak, the boat slowly sinks. If you are not on shore power then get a solar panel on it and make sure you don't accidentally turn off power to the pumps.
The weird place on my 23 that had a slow leak was the scupper. The port side brass tube had corroded through but you couldn't tell except for the slow trickle in a flashlight beam after crawling into the transom and laying on top of the motor. The wood backing block was jello from the leak - it even leaked in from rain on the deck while sitting on the trailer. There are more threads here about scupper issues than I can count and 4x as many opinions.
The good news is that after it has been in for a while you quit worrying as much...