[Christian]

One thing I do is to use a custom perspective which just shows me all my available tasks, from all contexts and all folders and projects except someday/maybe (or equivalent). Although I have contexts and perspectives for work, private etc it helps me to once in a while open up a long list of all the things waiting to be done. Glancing over them I often am reminded of the fact that I wanted to look into something and that's all it takes. It also helps to sort this list by something that makes sense for you, projects for example. That way you will be reminded that you wanted to do something for project x.