How to Monitor Your Credit Score and Credit Karma

Sean in California says you've been a great influence on me over the years. I find credit karma to be useful as it helps break down every aspect of my Equifax Trans Union score which fluctuates right above and below 800. My question is regarding my American Express gold card which does not have a set limit but when I log into AMX and check the spending power calculator, it gives me an available balance of $80,000. Are there any tricks you know of that would apply this AMX available credit to my overall credit available to usage percent? It would definitely boost my score.