How do I CFrame relative to a part's current position?

It's as simple as this:

(Example script) - This would move the part relative to another parts location:

Part1=script.Parent
Part2=game.Workspace.Part2
Part1.CFrame=CFrame.new(Part2.Position.X,Part2.Position.Y+10,Part2.Position.Z) --This would move "Part1"  exactly 10 studs above "Part2".

(Example script 2) - This would move the part relative to its location

Part1=script.Parent
Part1.CFrame=CFrame.new(Part.Position.X,Part.Position.Y+10,Part.Position.Z) --This would move it exactly 10 studs above it's previous location.

So basically, you just use Position.X , Position.Y , and Position.Z to get the Parts positions, then you subtract or add to get it to where you want. Anyways, if you have any questions, please leave a comment below. Hope this helped :P