This will get better with practice, but here is a simple idea to help. I hear some people talk of hand rubbing? Maybe this was in a book? Anyway it sounds like one of my methods. When you get lucid rather than explore and play, focus on solidifying you body. Look at your hands (thank you Castanada) try feeling something like your other hand. By focusing on a small simple familier scene (your hands) you can bring more clarity to your mental functions. When you see your hands clearly and feel like your thoughts are kind of clear, go and explore. If you start to slip out of focus, stop, look for your hands again and touch something (maybe a tree trunk) and really limit the veiw (just a hand and tree trunk) regain your composure and then go back to having a good time.