Plan your route. Go to the waymarking home page, make sure "show map" is checked. Click "search from map center" and adjust your filter as needed and move the map along your route searching for waymarks. Use the above mentions method to download them. I don't download every one sometimes, just some to get me in the area if there are a lot.
Another big help, print a list of the categories. Review them a bit. This works great if you have a "navigator/shotgun" riding with you. Some will jump out at you as you drive down the road (water towers, McD's). You may not want to stop for each and every one, but that water tower that looks like a peach may speak to you ("come take my picture"). Then when you stop for lunch and you see that giant ant statue across the street you say to yourself "thats a waymark!" so you get it (post if no one else has found it, visit if someone has).