Im looking to get tint for my windows soon, but they (along with my t-tops) have various scratches on them . Does anyone know of an effective method of remove scratches from the surface of glass ?

If you run the tip of your fingernail across the scratches and your nail catches they are too deep to buff out. If they are shallow a good glass shop can buff them, or you can try yourself (Eastwood sells a kit to use with your drill or polisher). I have never had any success with this issue but have heard of some that were happy with the results.

Anything other suggestions ?

What caused the scratches? Depending on how deep as previously stated you may or may not be able to remove them. With my car I know the outer weatherstripping sweeps caused it. They've gotten really dry rotted and hard. When I first bought my car my windows used to be so clear, people would ask me if I was going to roll my windows up even though they were already up. The scratches are so deep that i'm going to have to replace my glass now.