Gardening has an insane number of ten minute tasks, or five, or even one. The sheer number, however, can be overwhelming. The key, however, is to keep your motivation up no matter what you're doing. Here are some methods that work for me:
Puttering - Set aside ten minutes or more for just doing whatever catches your eye. Could be something minor like pulling dead leaves off a shrub but that's not important. What IS important is that you're doing something that gets you into the garden.
Work from your door outwards - This simplifies the choices, reduces overwhelm. Again, set yourself a period of time. This makes work easier but the weeds are still getting bigger toward the back of the yard.
Do a few minutes everywhere - Walk around and make every area look just a bit better, fewer old stems or straggly branches. This is good for keeping your eye on the whole garden and often avoids problems before they get out of hand. You'll see which plant needs more water, which one isn't thriving and may need more fertilizer, which has aphids, all those little things that add up. And you'll get the satisfaction of seeing the whole garden spiffed up a bit.