We aren't adding glory to God when we glorify him, we are ascribing praise. John Piper has a great analogy where he talks about how we magnify things. You can either magnify things with a microscope or you magnify things with a telescope. When you magnify things with a microscope, you make things that are really small look bigger than they actually are. But when you look at things with a telescope, you look at things that may be very grand but far away and hard to see, and you make them look more clear. So that's what we are doing when we are glorifying God. Not adding glory, but making His glory easier to see. That's for us and for those around us.
I glorify God when I confess my sin. I glorify God when I admit that I'm needy and that I need the salvation of the Lord. I make God more clear to myself and understand God more through the reading of His word through prayer, through meditation, of His goodness in looking at His scriptures very specifically and purposefully to understand who He is. I can make Christ more clear by hanging out with other believers in fellowship and seeing their lives and seeing how God has worked in their lives. It's important to understand that glorifying God isn't something that is a specific, A plus B equals C. God uses all different types of things to glorify Himself and to make Himself known. We can glorify God through how we use our voices, how we use our words, how we think about things, how we feel about things, how we use our emotions, how we express self control. There are all sorts of ways that we can use our own lives to worship God and make Him more clear to those who are around us.