Start from the Missouri Lakes trailhead, which is immediately to the left of the Fancy Lake trailhead at the end of Forest Road 704. If you have 4WD, you can drive an additional half mile up the road and join the trail there; you won't miss much except for a water pipeline and diversion dam. You'll have to wade across the creek if you use the 4WD trailhead, so unless you have sandals to stash on the other side or the creek is particularly low, it's best to start at the main trailhead.
Starting about a mile in, the trail begins winding back and forth across Missouri Creek, passing several small waterfalls and striking cliffs. The stands of confer you pass through feel unusually lush for Colorado. The trail climbs consistently through the trees, eventually opening up into beautiful alpine meadows as you approach the lakes.
More consistent climbing out of the meadows brings you into the Missouri Lakes basin. You'll have gorgeous views no matter where you look, dominated by 13,139 ft Savage Peak to the south. The next mile or so is a very gentle climb though several smaller lakes, with many spurs and footpaths if you'd like to explore a bit more.
Continue past the lakes for a steep climb up to Missouri Pass (11,986 ft), where you can simply enjoy the expansive views of the Missouri Lakes basin to the south and Cross Creek Valley to the north before heading back, or had a little further to join Fancy Pass Trail #2006
and make a loop back to the trailhead.
The lakes are also a popular fishing spot.