I always keep a pretty broad selection of dried legumes in the house, so one of my tasks prior to moving has been to cook and eat as many of them as I can. The plethora of practice has reminded me that while they are pretty flexible, there are definitely best practices for producing the best texture and flavor.
1. To keep the skins and beans whole, always soak first. Even for lentils, a quick 15 minute soak can help keep them from splitting open.
2. Soaking for at least 12 hours (up to 48 hours) helps them cook faster, and more thoroughly. Bonus: thoroughly soaked beans are also more digestible. Change the water every 8-12 hours if you soak longer than 12 hours, and refrigerate if soaking longer than 12 hours.
3. Lentils are very easily sprouted. Sprouting makes them a little sweeter, and a little more easily digested. Simply soak in a warm place for 3-5 hours. Drain, and cook normally. Note: cooking times will be slightly decreased.
4. Very slow and long cooking yields incredibly tender and creamy beans. For example, simmer for 60-90 minutes and then bake at a warm temperature (170 to 200 degrees Fahrenheit) for up to 4 hours. A slow cooker would probably yield similar results.
6. Cooking in flavorful broth, with plenty of herbs/spices, or with generous amounts of aromatic vegetables can impart flavor to the very center of the beans. Saute carrots, onion, celery, garlic, etc and cook with the beans.
7. Fresher beans are a little better– very old beans never do soften up properly.