Something that usually looks good is a biotope. It's like a cross-section of a particular ecosystem. There are tons of biotopes out there. Do a search...you should get a lot of results. If you want something else there are tons of options to choose from. You could do a planted tank, or a rockwork tank, or a blend of the two. Bog wood also looks really cool but most types of bogwood will affect your PH and color your water so make sure your getting what you want. You could also do the neon plastic tank. I don't like them personally but some people must. Buy yellow pink blue and purple gravel blend it all together and put it in your substrate then buy a few neon "rocks" at wallmart. You may also want to add some brightly colored plastic plants to the setup. When it comes to fish I usually pick a centerpiece fish and design around it. Taking into account aggression (lots of hiding places if highly aggressive) favorite temperature (make sure all your fish are comfortable at the same temperatures) adult size (don't by a fish that won't be happy in your tank when full grown, and don't buy fish that will get eaten by other fish in your tank) lots of factors to consider. There are tons of different combinations of decor you can use. take a look at the pinned topics on sand and rocks and any others that catch your interest. One other thing you can do is look through the member's aquarium and fish pictures forum to help you get some ideas. If you have any trouble finding these things let me know and I'll round up some links for you. Hope that was helpfull.