Hard to say. I like to lean forward and to the side, lifting one butt cheek off the seat and then I do sploosh with relatively much pressure.

One mistake I've made at first, is to be a bit overzealous with the wiping. In order to be clean, you only need the outside of the sphincter to be clean. Trying to clean beyond there is rather pointless, as that's the inside of your rectum, where your body literally stores shit.
But with toilet paper, you can obviously reach beyond that, which will return a stained toilet paper and make it look like you weren't clean yet.