Dont be afraid of tying leaders. It gets much easier in a very short period of time and not a lot of practice will get it down.
The FG knot is my main go-to. It passes through guides easily and is probably the strongest knot for leaders. It's easy if you maintain tension while tying. It will take a few times to get it down but every angler should know this knot, especially if leaders are used.
Over time, I learned a tighter FG than his produces a better and thinner knot. Here's my preferred method: Pic link:
https://ibb.co/9wvYSH9
One key is to have the braid tightly wrapped around your ring finger and pinky, so it doesn't slip. Spread the loop open tightly with your index finger and thumb. Spread the loop with good effort with those two fingers.
Your middle finger does all the work pulling the fluoro or mono through while keeping it taunt. Your back and forth wraps with the mono/fluoro are done by your free hand.
It may take sometime to figure out the correct size of loop to maintain so your middle finger doesn't collide all the time. Once you do you'll be tieing it in under a minute.
The other key to this technique is to keep the mono/fluoro anchored so it's as tight as can be, with a short working length. I'm sitting down when tying so I put the roll of of mono/fluoro under my right thigh and have a working length of about 18" coming out.
The widest part with this knot will always be be the trimmed tags. Make sure to cut them closely without nicking the other line.
If you mess up midway, use fresh mono/fluoro otherwise you would be tieing with kinked weak line. This could cause the knot to fail, so fresh line is a must.
Others may also prefer a modified albright but that's not my cup of tea. Also commonly recommended is the GT knot but it doesn't spread the load. It's only 55% as strong as the FG knot. GT knot will fail prematurely.
Good luck!
Fred