I think communication is definitely important. You both have to be open about what you like and how much sex is ideal for each of you. If you are open to exploration, you can also probe your partner about fetishes or sexual fantasies that they might want to explore. This also requires open communication without judgment.
There are a lot of factors contributing to sex drive decline. Eating healthy and exercise helps. Also, prescription drugs can effect sex drive depending on the medication, so it might something to look into.