Here are some tips wich I have found to be helpfull:
1)Make sure you have a good Internet Service Provider (this is crucial).
2)Ensure that you are using the latest modem sftware upgrades(I was getting connection rates of 28000 BPS on my 56k modem,then, when I got a V90 software(small download file)upgrade from the Modem`s web page,it shot up to 52000 BPS!
3)When playing EAW online,you can try changing the "Enemy force size" down to small/medium and set the "weather" to clear.
4)Make sure you have no other programs running in the background(like,anti virus software,Scheduling agent,soundcard launcher,task monitor etc etc....),all these things take away a lot from your CPU`s horse power.
A way to disable virtually everything is:
Go to:Start/programs/Accessories/System Tools/System information/Tools/System configuration utility/Startup(phew!);I have unticked everything(you can create desktop shortcuts to all the things you need to access instantly(rather than have them permantly "hovering" in the background,eating your valuable PC`s horse power ).
4)You might want to try Roger Wilco comunication software(its free)and seems to work pretty well.You can get it here:http://www.resounding.com/
5)There will be times when the Net is busyer than others,It is not an exact sience regardless.
6)Make sure your buddy`s setup is good to .
I am sure there are more tips ,buts that all I can think off at the moment mate.
Good luck and good hunting