What to Spend With Starting RP

You no longer get 400 RP, and isntead get a rigged hextech chest+key with particular contents.

Still for older accounts who have it sitting around, getting a skin when it's on sale (or perhaps through the 'my store' thing) seems like a reasonable use for it.

I don't think that is done any more, I may be wrong though. From what I've heard you get a free Hextech Chest to open. What is in it I have no clue at all.

You can grab a champion on sale with that RP.

I know people usually advise against spending RP on champions, but it's worth it when you're just starting out. Every champion you get at that point is a huge addition to your pool and to the champions you're familiar with, and the IP you can save can go to runes later on.

If you absolutely can't spend money to combine it with Riot points for skins you want, your options are somewhat limited. They are as follows:

1. Wait until a 750-price skin you want goes on sale, though this could take quite a while. If it's a 975 skin you want on sale, the price will be 487, though if you send in a drawing to Riot, you could get the 87 RP you need. http://www.riotgames.com/will-draw-rp-history-player-support-tradition
2. Pick out your favorite player icon and either a hextech chest or a hextech key.
3. Either 2 hextech chest+key bundles or 3 hextech chests/keys.

Hextech chests are far easier to earn than hextech keys, (If you get one on your first game, it's because their drop rate but you can only receive one chest for each champion, so if you play the game enough, you should end up with more keys than chests. Use your discretion on what you want to get.

buy jax for 282 rp when on sale or a 450 champ with rp