I enjoy cycling until nearly sunset. It's my favorite time of day to be out there. So for me, it's easy to wait until late to find a site. I will have eaten hours earlier, so I'll just have a quick snack before bedding down.

Good tip above about food storage being a priority.

If I'm in a truly stealth situation, I can pitch my gray tarp pretty low to the ground and lay my bike down. Knee-high grass will nearly hide me.

Another reason, at least this last summer, to wait until late to pitch camp is the heat. If it's buggy out, you don't want to get into a tent while the sun's still out in the early evening and it's 98F.