I've just built a bunch of a recent trip. What's making you afraid?
You can always book FP for when you want, add it to the plan, and then click "optimize". It'll rearrange around you. That's what I did, and it seems to work well. Plus, you can adjust the sliders if you want to build more time for walking (or minimize walking rather than wait time). I moved mine to "relaxed" because I've got a toddler and also want to take time for photos between rides.
TP's were very efficient for me on past trips, to the point that I never even used the old FP system. This is my first time with the new FP+, but so far the planning is working well.