When you right click on the panel one of the options you get is to modify the panel settings. There you change the placement of the panel, its background, and what type of applications and applets you wish to display. I personally like to have a little transparency on the panel.
LXDE does not have compiz as a feature but there are some good compositing tools you can use. If you are running Debian Whezzy you have the option of running xcompmgr. It gives you some basic compositing effects and allows you have a 3D dock if you prefer. It runs on the command line and you have to set it to launch on startup. You can plenty of of information in the Arch Wiki on xcompmgr. If you running Jessie or lubuntu 14.04 or later you can run a fork of xcompmgr called compton. Compton is not available in Wheezy if it was I would be using it. It is more stable than xcompmgr. The Arch Wiki has more great info on how to use plus the Lubuntu blog has a great post on how to use it on LXDE as well. To install just enter sudo apt-get install xcompmgr or sudo apt-get install compton in the terminal.
Themes and Icons
LXDE comes with a few predefined set of themes and icons. However you can add more to further customize your desktop. A good place to look is gnome-look.org there you can search and download what ever set of themes and icons you like. They come compress so you would need to extract them. The uncompressed folders need to be placed in ~/.themes and ~/.icons directories (you will need to create them if you have not already). Remember that since they have a "." at the beginning of the folder name that will be hidden in you home directory. So in order to see what is in them on the cli you need to enter ls -a and in your file manger you will have to use CRTL-H. Once you have them in those directories then goto applications (LXDE icon on the panel) -> prefrences -> customize look and feel there you can set the themes and icons to the ones you selected. I chose Numix-N_OB and Nitrux for my theme and icon set.
Guake is a top down terminal. It runs in the background and you use F12 to launch. It is awesome if you want to do quick terminal editing. You can install with sudo apt-get install guake.
Here are some screenshot my LXDE session: