Clothing, ab clothing really helps with getting into "little space" onesies, pj's, fun print tee-shirts ect. It doesn't have to be expensive, hell my first pj's (union suit) was from target and Walmart something like $10.00 I still wear them occasionally to, I also like browsing ab websites looking at different clothing, bottles, pacifiers, diapers ect.
I could write a book of all the great little things to do, but it has to be stuff that you really like to fully enjoy it.
1. Clothing: Dress little. Diapers, onesies, overalls, sleepers, socks!
2. Atmosphere: Blankets, pillows, even soft or playful background music can really set the tone.
3. Play! Playing is a little's primary mode of learning and exploring. Experiment with toys/games that you find enjoyable. I would highly recommend blocks/Legos, as they leave a lot of room for imagination, and can be SUPER fun to destroy after you're done building! Coloring is also really fun.
I've got to say, for me nothing beats crawling around on the floor in my diaper and t-shirt while playing with blocks. I concentrate on building the tallest tower yet and then...TEAR IT DOWN!
Having space to be yourself is very freeing indeed. Enjoy it!