playing lulu like as a DPS support is the easiest way to use lulu (easiest with the best out come). she becomes an effective back up in battle in a completely different way. rather than casting whimsy on your team mate in battle cast it on the person there fighting when they are using a ability to cancel it out (this works on some ability not all. it even works on some ulti's such as caitlyn's Ace in the hole. also try not to ever use help pix on a team mate who attacks slowly unless they are about to die. try not to take to much focus away from your team mate unless you know you can kill the person who is coming after you. use whimsy on yourself at times to get away or to chase down kills. stay far back and use help pix to hit people with glitter lance when low on hp, don't just leave the battle to heal, if push come to shove use your ulti on yourself.

these are the very best items for a DPS lulu due to the fact that she is supposed to be attacking constantly at the same time as supporting. supporting is not always healing and buffing. it often can be debuffing who your team mate is fighting. malady and black cleaver do this pretty well. also she is a mage so some AP is needed and top it off with some life steal and crit to help her stay in the game a little longer.

always pick bottom lane, don't take a lane on your own it is very hard to stop farming on your own and can result in the opposing team have to much of a boost over you. try to team up with a fast attacking team mate melee or ranged are just as good as each other and if they have a good AP attack than that's even better. just avoid teaming with someone who fights at a longer range than you (caitlyn, cog mor, etc) or someone with too little hp (shaco, teemo, etc). once you are have a good team mate (a alister, nidalee, ziggs, mordekaiser and a couple of others are the best team ups) you want to start with spamming glitter lance anytime you have it. while casting help pix on team mates who are about to engage in a fight or on a person trying to run from one. dont be afraid to continue battling if your team mate is about to die,if you give up to early he may not get a kill, wait to the very last second and if he dies cast all your spells on yourself and shoot the person chasing you with glitter lance and go back to turret, keep using glitter lance to slow down farming while waiting for your team mate to comeback. once you have wild growth this is when you can really push.

Lulu cant do much while being ganked, her only hope is to try and flee. use whimsy on yourself and help pix on your team mate and wild growth if you have it. run back to tower or a team mate if he has come to help and than use glitter lance if hopefully your team mates help pix had not run out and you will be able to assist him from a far while dealing with the gank. try to stay at a range from him while keeping all your stacks on him so that you have an advantage on him. use ignite if you have to and keep using glitter lance and even help pix if the fight lasts too long. ganking is still a good way to stop your lane seeing as a lot of the time to say yourself your team mate may be killed.

If you have not been doing to well than it is best to just support with constant ganks on middle lane. don't stay to long and try not to go for the kill you may not get it any you risk getting killed.

lulu late game benefits greatly from barons buff convince your team if they are good enough to take baron. once you have barons buff you and your team should all take middle. this will force the other team to defend it. this is a good thing because now you can really get some kills. use all of your buff on different team mates (whimsey on mage, help pix on ranged DPS and wild growth on tank) than go to the front line and attack focus on the other teams melee dps, than move to there support or caster, next to the tank and if they have not fled by now there ranged dps. Doing this once or twice should win you the game.