I'm a huge Battlefield 2 fan and I've been playing it for about 3 years. Under the time I've racked up around 260 hours playtime. During these years I've picked up a couple of tweaks that make the game more enjoyable because honestly it's not perfect. It might be interesting for anyone still playing it.

#3
Remove the intro movies
Since you will be starting the game up countless times these things get really annoying. Getting rid of them is really easy and will not set off Punkbuster either. Go into your install directory. In my case "C:\Program\EA GAMES\Battlefield 2\mods\bf2\Movies". The files you will be changing are:

Dice.bik
EA.bik
Intro.bik
Legal.bik

Don't change any other files because might stop your game from starting properly. First you might want to check if you have "hide file extensions for known file types" turned off. Create a new folder, name it whatever your want and move the four files there. Go back to your "Movies" folder. Right click and create a new text document and name it "Dice.Bik" for example. Do this with all four files and their respective name.

#2
Get rid of the music
This might only be me but I fucking hate the music in Battlefield 2 because I have heard it to death. You might think dragging the music volume slider to zero would help, but no. This only mutes the music in the menu but it will still play during the loading. Since you will spend a lot of time looking at the loading screen it gets annoying. The folder you will be fiddling about in this time is "C:\Program\EA GAMES\Battlefield 2\mods\bf2\Levels" In this folder you will find a folder for all ranked maps in the game.

Open one, "Strike_at_Karkand" for example. In here open the folder "info" and the open "Strike_at_Karkand.desc" in a texteditor. Look for the line:
<music> common/sound/menu/music/load_MEC_music.ogg </music>
change it to:
<music> common/sound/menu/music1/load_MEC_music.ogg </music>
So what you will be doing is adding a "1" after music in every .desc file. You have to do this for all the maps or you will still hear it.

#1
Get Xfire!
The browser in BF2 is horrible, period. Get an account for Xfire and download it at http://www.xfire.com/. It's so much easier to find the servers you want using Xfire. A bonus is you can jump into a server where your friends are playing without any hassle.

PROTIP:
Check out http://bf2s.com/ for all your stats and diagram needs.