Dave's suggestion to make your own checklists is a good one, especially for things that always happen at the same phase of flight. For example, something that you always do at Top of Climb could go on a personalized checklist. If you do make personalized checklists, just make sure to not omit something from the approved checklists!
That said, I don't know about you (and you don't say anything about where you're located), but one of the first few things I practiced doing even before setting out on my first cross-country navigation exercise with the instructor onboard, was to make a flight plan.
Now, I'm not talking about a full-fledged IFR flight plan complete with exact compass headings, specific wind correction, and so on. This was for daytime VFR flight, so much of that wasn't really needed.
What I did was to sit down at the kitchen table at home with an aviation map of the area and a flight plan form, decided on checkpoints, and figured out how to get from one checkpoint to the next, including determining the distance. For each leg, I'd note things like altitude restrictions (above 2000 ft AMSL here; specific clearance (from whom?) or below 3000 ft AMSL there; ...), a rough compass heading (I was navigating by landmarks, not instruments, but knowing whether to aim for 200° or 160° for a southerly leg was helpful), frequencies and call signs, and so on. Once done, I took a highlighter pen to a copy of the map and marked the planned route; I then carried that copy of the map, the flight plan, and airport directory sheets for both the intended airports as well as all other nearby airports, with me.
Once you have something like that, there is no real reason why you couldn't mark a checkpoint with some sign or text that tells you that you need to do something in particular. You could, for example, write "tank" in the margin to remind yourself that you should switch fuel tanks around that point, or "call XYZ 15nm" to remind yourself to call someone in particular and report your position as being about 15 nautical miles out.
While you should still be able to fly safely without any of this (so you do need some mental picture of, say, where the nearest airport is should your instructor suddenly tell you that "you just lost all your maps, and the radio's shot"), everything that you do on the ground before takeoff is usually one less thing you need to spend significant time and mental energy worrying about while in the air. Choose wisely which things to spend your energy on while you're actually flying.