I have done some test with the littlefee shoes I own on my Soo.Most fit nicely but, it can give big foots.
Fairyland Ribbon Shoes
The doll can stand on it own, but the foots are loose in the shoes, so it can easily fall.It better to wear it with sock.
Fairyland Macaron pink Slipper
It perfectly fit and the doll can stand on it own.It similar as if the doll had no shoes
Fairyland Basic Boots
It perfectly fit and the doll stand on it own.The doll stand more safely with this boot than the other shoes i tried.Probably the best one.
Perfecty fit, the doll can stand on it's own, when her feets are not close to each others, otherwise the doll fall...
In the shoes I tried, the Basic Boots are the best one.If you want to wear LFT shoes i recommend them.The others can all stand but not without risk.