I think you handle the aperture just fine. You have some nice composition ideas too! Sländan är det bästa fotot! ;)
Hmm, if there is something I could add to the criticism.. The light in this pictures are what drags them down a little. When photographing, try to be out at either dusk or dawn. Then you will have beautiful natural light photography. These shots look like they were taken at daytime.
To notice the huge differance, try taking two pictures of something.. Like a tree or a bush or whatever. First take one in daylight and then one at sunset. You will notice a huuuge differance and then never take a single shot in daylight after that! ;) Nah, but really, daylight is like nuking the photo. Avoid that!
Also, you could try a close-up filter for your kit lens. I have never tried one, but you will be able to get a little closer. Or when you have money, get a macro lens. If macro is what you wanna do. If not, then I recommend you wait with the macro lens and buy a wide angle zoom or a tele zoom. Very good to have if you want to shoot other things than insects, which I suggest. There are so much more to photography than macro! An interesting style you could try is street photography. Just take random shots of random people. Sometimes you can get really good and cool shots! Check out
http://ferocello.deviantart.com/ to see what I mean.
Wtf, I always write too much.. Uh well.. If you have any questions, just ask.. :P
I'm getting my 350D this week or beggining of next week btw. :D