Uh, not sure about the waist size shrinking a bit part. My 35lb of weight gain this year has been accompanied by 4" of gut growth. Depending on your genetics, you'll put fat on your gut, thighs, hips, or maybe you'll get lucky and it all spread out evenly. I can still see my quads, but haven't seen any abs the last 35lb of weight gain.
Clothes shopping when you get more muscular is kind of fun. No more slim fit jeans for me. Nope. Stretchy relaxed fit jeans is where it's at now.