I start thinking about the various accessories on my wishlists. I think about the gear that I'd like to upgrade or the various iterations of products I would like to try and compare them to those that I own or have already tried. This usually helps. Then I also remind myself that "you haven't shot your _________ in months. What are you going to do with that?" or "you bought this months ago and still haven't used it." This thinking usually helps. What works for you?