According to the world's way of thinking the answer to the question asked in this title is that you "give" to yourself first. You make sure you have all your needs met. Then if there is something left over, you may treat yourself with something you want or something you want to do. Then and only then, you can consider giving to someone else... including God.
Granted, far too many of have a tendency to reverse the first two. Pleasure first, then needs and if there's anything left, someone else (God perhaps?) may have a slice of the pie. What if nothing is left after the first two things? Oh well, I'll just have to give next time... if I have the money.
I don't know about you but something about this just does not sit quite right with me. I know this is what the world would say but we're not supposed to be "the world". We're supposed to follow Christ and I wonder in this sort of situation what Jesus would really do? Would giving to God and then giving to others be at the top of his priority list or would it be at the bottom?
Before I go on, I want to make something very clear. If you are giving to get something, you are not giving. That's called buying. Giving is not the same as buying.
Too often we get into trouble and then decide that we need to "give" to God so that He will provide for us and get us out of trouble. In other words, we are trying to "buy" the favor of God. Folks, we can't buy the favor of God.
I've heard people complain about how they gave to God but nothing happened, they got further into debt or whatever. If you are talking like that, if you say, "I gave to God but He didn't give to me." you weren't giving. You were trying to bribe er... buy God's favor. Stop doing that because God cannot/will not be bought. In fact, such actions displease and anger him.
The other thing we might do is treat God like He is some sort of vending machine. We put the money in and voila, we get a prize. God is not a vending machine. He is not some sort of genie and He is certainly not our slave. He is God and we are subject to Him; not the other way around.
God wants to be first in every area of our lives, including our giving. When we make God first, before anything else, we are demonstrating not only our love for Him but our dependence upon Him as well.