One of the best sex advice for couples between the sheets is to set the mood. Creating a romantic atmosphere is easy.
Start with a clean bedroom, light some candles, put on some music, have some drinks, and start romancing your sweetheart. It can be great after a stressful day or week.
Sex is ultimately a result of what we do to improve our emotional and intellectual connection. One of the best ways to make sex more interesting is to treat sex as a culmination of reconnecting after a stressful day or week.