In the book “Exploring the World of Lucid Dreaming” Stephen LaBerge mentions how you can prepare for this technique by keeping a lookout for random things every day and do a RC whenever you spot them.
I have considered an alternative to this which should work just as well - I was thinking that instead of choosing targets from when I wake up I will think of one target at a time throughout the day that I am supposed to notice in about 10-20 minutes, for example I will do a RC when I have reached a certain destination, then another one when I see a car with a certain colour etc.
This way to do it should be very similar to when you prepare to notice dreamsigns during WBTB, since those will also appear in perhaps 10-20 minutes.
I did this for a while last summer, and it definitely helped developed my RC habit. I’d forgotten this though, as I’m trying to reestablish those habits. Thanks for reminding me!