I seem to have trouble with a lot of one handed stuff since I don't have very big hands.
Really have no idea what to do now =D.

Basically you just keep practicing. What type of magic are you working on?

One handed stuff like what? Charlier cut? Palm? One handed fan?

*a lot of one handed stuff* ...means..what...?
In this specific case ( card sleights )...size doesn't matter ...most of the time
I have also small hands...but after some ( more or less ) time of hard practice, I was able to do all the stuff I worked on...just take your time...

But if you think you are not able to work properly with pokersize cards...you can try bridgesize ( I wouldn't ... )

Yeah mostly I noticed on fans that I couldn't make a nice spread fan. But I'll keep trying though.

I've seen some really nice one handed and Carnahan fans posted by teenagers and kids on Instagram. Practice practice practice

Practice will get you far. Trust in the process. The more you practice, the better you will become.

Ray

Practice and change up the position to fit. I have smallish hands and find that I need to pinch the cards closer to my middle finger for a wide even fan. it's all just minor adjustments amnd finding what works for you.

I also have small hands. At 5'5", they are just right.

At first I adapted by using USA quarters and bridge sized cards.

Now I can use USA half or old Morgan dollars.

I used to think I had small hands as well until I compared hand sizes with two full time pros I worked for as a stage hand. One had hands slightly longer than mine, the other slightly shorter. After that, I figured out that hand size doesn't really matter. The real trick is figuring out how to adapt any move to your individual hands since nobody has hands exactly like the originator of a move. And since any individual who has invented a specific sleight probably didn't invent more than 5 to 10 at the most, any given move was likely invented with a different set of hands that worked a sleightly--pun intended--different way. So every move you learn will have to be adjusted to fit your hands. You also may find, as I have, that I take a move and not only adjust it to fit my hands, but radically change it and invent a totally new sleight. Another thing to keep in mind with any move is the amount of pressure you are putting on the cards. Too much pressure and the get "greasy" and slide around. This can be a problem with one handed moves in particular.
I hope that helps.

Having small hands myself I found it takes longer to learn moves. You got to keep practicing until it feels comfortable

Some people have small hands, some people have "windows" between their fingers, some people have dry hands, other have sweaty hands, etc. Whatever move works well for one hand type might not be as easy for another and vice versa. I had a hard time learning how to palm, but I succeeded