I have heard way too many stories of couples losing that loving feeling, then throwing away the marriage because of it. You can get the feelings back! It's a fact! But, the things I recommend are not things you 'try' they are things you 'do'. It has to become your way of living. It's a relationship lifestyle change that must be permanent ... the 'new you'.
1) THINK of your partner in positive ways.
Sometimes when the loving feelings have left we can't help but think of our partner in a negative light, but just refuse to think of the negative and think of the positive. I realise that there may be situations that make this very difficult, but do it anyway.
2) TALK of your partner in positive ways.
When you speak of your partner, speak well of them. Don't slam them or gripe and complain and be all negative. Make sure to compliment them often. This will help you begin to appreciate them once again.
3) DO the things you would do if you had those LOVING feelings.
Feelings follow action! So ACT like you do have the feelings, and you will have the feelings! You don't have to feel like writing a love letter to actually write one. You don't have to feel like saying, "you are beautiful" to say it. You don't have to feel like buying flowers to stop by the florist to buy some. Just do it.
Seriously, I don't understand that we have rules we live by in life, but we don't apply them to our relationships. For example, you don't only go to work when you feel like. No, you go because you are committed and you have a job to do. You don't only change a diaper when you feel like it. No, you change it when it needs to be changed. You see, we should live this way in our relationships ... be committed to LOVE, then love every day for the rest of your life!
They say, "The grass isn't greener on the other side of the fence, it's greener where you water it!"
Bonus Point ...
4) Give lots of KISSES.
Kisses make everything better! Lot's of physical touch is important to get the feelings to return. Making each other "feel" good physically are always helpful.