I used to love drawing and sketching but can't seem to settle down and do it--used to spend HOURS on it--scenery, animals, portraits, fanciful images, etc. My SIL got me a new sketchbook and beautiful pencils for Christmas and I drug out my old drawings and am going to try to re-inspire myself.
I like some crafy things but I am a cheater. I use my glue gun a LOT and love making my kids' Halloween costumes. I also really like finding scraps of material, ribbon, beading, etc. and using nuts, which I glue together with wood glue, paint, and decorate into small animals as Christmas ornaments. That doesn't take a ton of time all at once and I can start and stop as I like as long as I keep the projects on a plate out of reach of the kids. I haven't finished any for a while.
Summer hobby: FISHING!!! Thankfully, my boys like fishing, too. Sadly, I usually feel I can't justify my own fishing license, so my husband usually buys the license and I take one kid for a hike while he fishes with the other and then we switch. So add hiking to my list as well. :)
Newish "hobby" (quite embarrassing for a girl who only ever owned a pair of hiking boots and sneakers) is shoe shopping. Expensive if you buy, super fun if you can just try on some really hot new heels and think about wearing them to work. Awesome if you find a great clearance deal. Not so awesome when you're nine months pregnant and can't handle putting anything on your feet at all. :) (I prefer to be barefoot anyway, but if I HAVE to wear shoes...may as well have fun, right?)
Books and antiques--I'm a book collector (will never own a Kindle unless some mad soul buys me one, but I will return it and buy books). I love the smell, sight, and feel of books, especially older books. I don't have a lot of time to browse antique stores or used book stores, but sometimes that is my Saturday morning break after I let my hubby sleep in--I head over to the antique store in town and just wander and see if anything grabs me, even something small like a handkerchief, or old bookends, or a book. That is as cheap or expensive as you let it be. I find the experience of the store very soothing though and don't always buy anything.