You've gotten some great advice here. I was just FMQing this afternoon and thinking of all the things I've learned in the past few years. Follow the tips from this thread and you should be on your way to some nice, enjoyable and pretty FMQing.

My tips? Don't go too fast or too slow. Find the middle ground that works for you. Don't worry at all if your stitches are the same size or not. They won't be and no one will care, not even you, when the quilt is finished. They just can't be so big they'll rip out easily! Do not EVER watch your needle. It isn't going anywhere and all it's going to do is go up and down. Instead, look ahead an inch or two to where you want to go. Wear gloves. I literally can't quilt without them. Mine are Fons and Porter but some here like Machingers. Buy one or the other, but buy some! Don't let the quilt drag down. It needs to be supported on a table and on your lap. I used to pile books around my machine before I had a built-in table! It will certainly make your stitches wonky if the weight of the quilt is pulling it away from the needle. It's good you are keeping at it and not giving up. It is loads of fun once you get the hang of it!