If you have not yet seen this article, check it out. Its very useful.
Point #4 gives three basic design shapes for your tank. Right now, you don't have any of the three. Especially if you are a beginner, I recommend trying to get your plants into one of the mentioned shapes. Given the positioning of your driftwood, I'm thinking that your tank would lend itself to the concave layout - but, you need to pick what you think will work best.
Hope this helps.
By the way, congrats on the progress. Your tank is filling out nicely. Just need patience.