South and North Twin are great float tube lakes and easy access. They get busier on the weekends so if you can do a mid week trip I think it is more enjoyable. Kick around with an Olive Bugger or Sheep Creek and trail a Poxy Back Callibaetis or Ice Cream Cone. Or sit with the indicator rig and a balanced leech and ice cream cone suspended under the bobber. Likely to see some mayflies (callibaetis on the lakes) hatch and should offer some dry fly fishing.
South Twin resort has good burgers and milkshakes by the way.