If you're playing Bard for fun, but don't want to be feeding and all, you might want to try this guide. It definitely works. It makes you reduce your number of bard deaths into a single number, as long as your playing skill is at least silver.

With Season 6, Masteries have changed, and so I've updated my guide about Bard's masteries. With these new masteries, surprisingly Bard has a higher survivability rate. Lol.

As for runes, I have yet to find the perfect runes. Meanwhile as a substitute, I suggest taking AD Runes, because you're going to help poke your enemies as a sp using AA (and this is also to get the extra gold for your Spellthief.)

1) Spelltheif, 2 health potions and a mana potion.
Your Spelltheif is what you're going to use for earning gold while poking. Bard's passive with the meep allows him to attack so-called "2 times at once". Thus, you can earn 10 gold at once while poking your enemy.
Spellthief is also going to help a bit with your mana regen.
You have no problems with mana when chimes are already around.
2) Secondly, you need Randuin's Omen for the extra hp and the armour since you're a support and you're going to be fighting an ADC.
The Active Randuin can slow, so you can quickly run.
3) Then your boots of swiftness is there for you to run faster than a wild Yasuo paint-brush. Most of your escapes are done by using your Q, E and R.
4) Frozen Mallet gives you a lot more hp, and also allow you to slow your opponents with an AA while you continue your running.
5) Your Spirit Visage is there to give your Magic Resist and also hp. Actually, you'll need the MR more. But depending on the situation, you can always try on another item with MR. The thornmail is not a neccessity either, it's just there if you want it.

MAKE SURE you always take heal, even if your adc has heal. There are going to be countless times you're going to die, but these 2 heals will always make you live by a bit of hp...

1) Learn your W first for heal or Q if you want to poke.
2) Your Q is good for initiating fights, running away and poking. It's especially important to learn how to stun with Q.
However, the best way to poke is with your AA. Poke only when your meep is present by the way. It would be more damage in one AA, and with Spellthief's edge, you can get more gold. Also, learn to poke until the enemy adc is half hp. That will force them to use a health pot and hate you at the same time. >:D
3) W is good for healing after it's cooked (matured, I mean). Use it in moderation, do it more often if there are lots of nearby chimes so you can have your mana back.
4) E, your magical journey, is really useful. Mostly used for you and your adc to escape. When an enemy jungler is incoming, use E to escape together with your ally. If the enemy follows your E, be sure to have your Q ready to stun him.
5) R, your ulti, MUST be used wisely. Preferably for using on enemy champions.
It'll allow you and your ally to chase the target, or get a 0.5sec advantage to deal the first strike, or if not, for running.
You will need to practice your aiming though. And DO NOT use your ultimate to engage a fight. Use your Q to engage a fight. Your ultimate is used in the middle of the battle, or after the battle. (This is for btm laning phase though).