Tack and Floss
One common way in fitness centers, cross-fit gyms, etc., to address acute issues in our muscles and joints is to take a lacrosse ball or foam roller, put pressure with it on an area and then move the joint. This pins down the fascia and muscular tissue and forces the other fibers around it to move and stretch in ways that they don't normally do. A common term for this is "Tack and Floss" - because you're tacking down the tissue and then "flossing" the fibers through and around that pinned down area. It's highly effective, especially if you're trying to relieve and release trigger points, knots, etc.
You can do something very similar to using rollers and balls with rubber bands. You can use something as simple as a bike tire inner tube, but they're making these "Voodoo" bands specifically for this purpose. The added benefit to these is that we can also create a large compressive force through the tissues in addition to the traditional "tack and floss" approach.
First take the joint in question and run it through full range of motion and note the beginning/end markers.
Next take the voodoo band – wrap it around/above/below the joint. Then run through full range of motion. Multiple times. The compressive forces help the tissues while also tacking down the muscle as you move through the full range.
Release the strap and retest your range of motion to see if improvement can be verified. Using this on ankles, knees, and elbows is the most common areas.