For some people, rock arrangement seems to come pretty naturally and they can get a good looking scape going in their first few tries. I am not one of those people. On my first 3 tries, I basically gave up and it showed in my final design. I figured if the plants were lush, it won't matter, but it did.
My biggest mistake was not buying enough rock. When you are new to this, it's much easier to have more options as you often don't know what you are looking for. I was buying more expensive stone at first but found some really cheap stuff that really helped me gain direction. Instead of having 25lb to work with, I found some stone that was 4 or 8 cents per lb. I was able to pick and choose from 150 lb of stone while spending quite a bit less. I ended up with over 250lbs of the stuff over time which made life easier. I wouldn't recommend going that overboard on a 10 gallon as you may just confuse yourself but I would atleast go double, if you are not using super expensive stone or don't mind soaking up that cost for future scapes/changes.
Second mistake, not finding rocks with both good shape and texture. I found stuff with one or the other but not both. Good shape is more important that good texture, IMO, but both really make the tank pop.
Lastly, just mess around for awhile. Use some old substrate or just sand and make a scape whenever you get time. Even if you make what you think is a masterpiece, ruin it, as you will find you only get better over time.
I am a musician that writes 100% of my material. The best advice I can give a beginning musician is to make a lot of songs when you are first starting, rather than perfecting your first or second song. You learn so much more quickly when you have to come up with more than a single idea and make it perfect. Me, not having much skill in visual arts, makes this necessary for me. I can see what I like but can't visualize my own "works". I can read all day about techniques but the practice is what helps me. The more scapes I tried, the more materials I had, and the more patience I gained, my scapes reflected that. Just buy an extra 10 gallon and start playing around. You will get way better as you do a few scapes and look at what you like and don't like.