How I did it: My fiance and I combined finances after several months of "ok, I owe you $42 for groceries, you owe me $52 for utilities, let's call it even since we went out for pizza last night" sort of thing. With our combined efforts and a goal to eliminate all debt from either of our name prior to our wedding, we were able to pay off all credit cards, student loans and build up a sizable savings account. I'm lucky my future husband sees our finances both as shared burden (debt) but also shared assets.
Lessons & tips: Well, it's been an interesting experience learning to share finances with someone. While we have similar spending habits the first month or so were a little exposing. I felt very vulnerable knowing that he saw every little thing I spent my money on and it was hard not to be judgmental when I saw him spending money on things that I would not. We're working on a balance between helping each other with excess spending habits while maintaining some level of freedom.
Resources: A supportive and open fiance.