I have an extra row of grommets sewn accross the front trampoline of my boat. I tied a line so it has loops sticking up from every grommet, and the line runs above the tramp from one grommet to the next. Tons of places to tie stuff down this way. I'll probably get one of those huge "Accross the Tramp" storage bags with the big clear map pockets on top of it for distance sailing.

I tie an igloo cooler to the forward port side of the mast beam. The line runs from the forward tramp grommet-line, over the cooler (actually through the handle), around the mast beam and back under the cooler. It goes around twice. This way I can push the little lever/button on the top and pivot the lid fore or aft to get at the iced drinks, without the cooler being able to come loose.