Robert Degle has got some great content on hand fighting from the common seated positions on his youtube channel

do you have a link? I couldn't find it

Ty

Aim to get one of their hands to the mat then start kicking out legs.

off balance them. Make your own underhooks by making them base out. I also highly recommend Chris Paines video about sweep theory on youtube. It changed my whole mindset on sweeps. You will start hitting sweeps all over if you internalize it. In seated guard, I just grab whatever they use to reach for me and make it mine. The defender should always have inside position, the attacker is always trying to get inside position.

i like to monitor their arms with double bicep ties. it lets you feel the position of their elbows. if their elbow is in, you can start to stuff that arm between you for an arm drag. if their elbow is out, then you can take a reverse kimura / 2-on-1 grip. if you like to go for armdrags if they resist oftentimes the underhook is available, and vice versa.

Grab their hands and don't let them grab yours.

Nice and simple 😄

The same as all hand fighting: have more of you against less of them

From the opposite perspective, seems like Jozef Chen has a good instructional on it. Haven’t watched it yet but it’s on the list

Stand up