Get 7-8 hours of sleep per night, period! 

Good sleep = good testosterone production, which as you know, is the hormone that gives us women our sex drive.

Also, eat more fruit, veggies, nuts, seeds, beans...and less meat, processed foods, saturated fats.  Diet can make a difference (Refer to your doctor or nutritionist for proper, more in-depth advice!)

Exercise can help too.

Sometimes if I don't feel like doing it, once I get into it with my hubby, my mind changes (we started scheduling our "sexy time" just for that reason, and it has been the greatest thing we ever did...even though it's not spontaneous, it works in other ways). 

Also, don't forget about the mental aspect of sex drive. Think back to your past experiences, what kinds of situations were you in when you were at the top of your game? Maybe you are lacking these situations which actually make you excited. Maybe you're just bored with your current situations.