LEG PROBLEMS

Massage should not be done on some medical conditions. If you have a medical condition please ask your Dr. before doing massage. 
Always avoid using your thumb to execute your massage techniques as the muscles above your thumb will wear out.  If you just can't help yourself be sure to get regular massage work on you thumb pad and the rest of your hand.

With most to all of conditions lack of blood and fluid flow will cause pain and eventually disease.

Leg pain will almost always be coming from hip problems. ie -- The hips are so tight that the bundle of nerves going down to the legs become pinched, also constricting the flow of necessary fluids to give the legs nourishment and the removal of garbage. (and kind of toxins like uric acid etc...)

So to massage the legs find not only the tension at the site of the problem but also all the muscles attached to the issue that are above the problem on the body.

Massage techniques.

Always move from the feet toward the head in most any massage. So if you are starting with the calf muscles work in long flowing motions toward the head. you can split the calf from the thigh if you want to do more detailed work which if you want to really get the tension out you should concentrate on each muscle group. 

Long deep strokes coupled with kneading the individual muscles will get most tension out. You may need to do more than one session for more long term problems. (Regular massage will keep the body in a more healthy condition. Healthy eating like vegetables and a little fruit is also key to staying healthy.)

For the thighs the above paragraph works as well.