20:1
I use the same leverage levels I get on HotSpotfx so that trading styles will stay the same and we won't take unnecessary risks just because I have higher leverage on one vs another.
But with Oanda, that leverage is misleading. At 50:1, that's the leverage you need to open a trade, but your effective leverage is 100:1 before you get a margin call. On 20:1, I still can go to 40:1 before margin call.