Whenever you go to get chimes and leave lane, assume that's when you're ADC is going to diving in to attack.
Okay, real tips.
Try not to spam your Q too much. It's strong when it hits, but its a waste of mana if it misses. Try to go for sure things.
The healing stations are helpful during the laning phase, especially when you want to roam and get chimes. Leave 1 or 2 around your tower so you can give your adc some healing if they get poked while you were gone.
When you use your E, smart people won't usually follow you in, but if they do, time it up for you can land your Q for an easy stun. If you're in Bronze, they'll likely be pretty stupid.
When you do roam for chimes, that's a good reason to place down wards in important areas and provide your team with vision. Roaming and wading is a good habit for supports in general, so try to start it with Bard. Just be careful not to do a bad facecheck and be picked off. It's good to always be doing something when you're moving around.
Bard's ultimate is probably the hardest thing to use, even if you're in an even higher rank. It can stop a tower from shooting you, stop your tower from getting attacked, or stop an enemy in place so your team can catch up to him. But it can just as easily hit your own teammates and potentially kill all of you because of it. The best tip for this is to improve your own shot calls and just practice.