How do you build her?

Thanks

Personally, I go for Prospectors Ring and sapphire crystal to start, and then Boots of swiftness. Depending on my mood I'll make Reverie/deathcap depending on whats going on in the match.

Honestly, things like this are a case of personal preferance, you're better off trying to find your own build that works for you. The first three I'd say are needed, though.

The once or twice I've played Sona on dominion I did AD Sona. Tri-force and then built tanky from there like FoN, Randuin's. She has surprising burst and not a lot of people expect it. For boots you can do mercs or berserkers, either are good choices. Play her like you'd play a ranged AD and she does rather well.

I play Sona almost exclusively at the moment on Dominion.

Theres a few builds Ive had success with.

I like to start with either Boots/Tear or Boots/Blasting
Boots/Tear is great for building mana by spamming your abilities, Sona can run into mana issues as your survivability and ability to kite can mean you stick around for longer. Tear makes this a null issue. I then build Ionian, Sheen, then from there you can either max your CDR for late game 60sec ultimate to control team fights and points, or finish your tear if you have the gold.

Boots/Wand goes into Ionian then Morellos for max CDR, then sheen/rush Deathcap, then survivability items etc.

Tear gives you the sustain you need to spamming continuously and when you finally upgrade it, you get some decent AP with your other items. Combined with sheen, and powerchord this allows you to push decent DPS. While the CDR early push (consider frozen heart over morellos depending on enemy team comp) is also viable, getting your chords down to 4.2 seconds each and your ult to 60 early on.

For masteries I either build a 21/0/10 or a 10/0/21 depending on what im building. Both work. You can have games where you go 6/6/28 or 12/2/18. it varies depending on your team comp and how good your team is.

how do you do 10/0/21 in mastery???

If I made a mistake somewhere, excuse me, but its 315am, and I posted between winning in dominion matches.

I've seen tanky support Sonas, they were pretty annoying because you can't really focus her first but she's a constant support for her team at the same time.

My build is boots -> Sheen -> Deathfire Grasp -> Rylai's/Lich Bane (which I rarely finish). I've seen others do extremely well with Deathcap + Morello's.

Masteries I use are either 9/21/0 or 21/9/0, taking magic pen and extra health. Magic pen reds, mana regen/level yellows, AP/level blues, flat AP quints. She can burst people down for a good 75% of their health with DFG + ult + Q + Sheen/Power Chord autoattack.

Her weakness is her low health and squishiness vs gap-closers like Pantheon and Wukong, which is why I like Rylai's and 21 in defense.

Trinity Force, Boots of Mobility, Glacial Shroud, Sanguine Blade then usually work on attack speed items. I always start with sheen and a health pot or 2 and mana pot. With her passive and sheen proc, she hits insanely hard and can carry quite well, surprisingly. The biggest problem is that she has no good escape mechanisms and can be burst down quickly if focused and/or CC'd. With a good team though, she is quite scary and can win games with a good composition of champs that work well with her.

The tanky ones are the most successful ones I've seen. AP/AD carry build on her works surprisingly well early on, but without any escapes she gets annihilated by assassins/AD casters later on. Tanky AP seems like it would be the way to go.