A pad by your phone is an excellent place to start. If you happen to still have a land line. A lined legal pad provides a nice background for almost any kind of pencil or pen. The back of an envelope works well. A paper napkin, a store receipt, a recipe you clipped from the newspaper, but never made. Whatever is handy, will do. Doodling does not require a moleskin.
I've been told spare time is for tweeting. Thumb something clever out to a network of those you'd like to know. Who hold membership in a club that just might admit you, if you tweet.
Doodles are a kind of tweet from the your own private universe. Postcards from the nether regions of your very own being. Your hand and mind taking a stroll while you are occupied with the details of a shopping list or where to meet for coffee. Doodles can sometimes hold a key. Unlock a story or image. Finding a page of old doodles is a great tonic for remembering. Or not.
Sometimes a doodle is just a doodle. And that's enough. Find out for yourself. Let doodling into your life.