Do to others what has already been done to you, as much as God enables you to do so. The idea of "freely give" is simple: someone gave you out of their kindness. Do the same with someone else.
I'd like to encourage you to ask God each day to give you an opportunity to share with others something already shared with you. It could be money, or clothing items that you have too many of, it could be a booklet you found most helpful to you, it can certainly be the Gospel, and it can also be words of encouragement and advice you found helpful. It can also be something simple as a smile. Point is - give. Another "point" is - keep what you have and miss the joy of giving.