For hobby use, it's up to you.
Industry standard goes like this:
Make sure you connector is clean and dry before connecting. Many non-hobby grade connectors for larger coax include a section of adhesive lined heat shrink tubing. If your connector doesn't have this, it's a good idea to put it on. It'll not only seal the crimp well, but it provides some strain relief.
Start a few inches below the connector, wrap some good electrical tape (Scotch 33+, not Harbor Freight). Wrap up towards the antenna. Each pass of tape should overlap the previous wrap by 50% (Half lapped). When you get to the base of the antenna, make sure you are not blocking any weep holes. Change direction and wrap back down to the starting point. This process is called "Half lapped and back".
Next, take your Butyl tape, start just below where the tape stops and wrap the entire connection with a slight overlap. Stop when you get to the antenna base, remember, don't block the weep holes. Then go back and by hand, mold the butyl tape in so all voids are filled and it's a smooth covering. There should be no visible seams.
Finally, do the tape wrap again. This time, start at the antenna base, wrap down with the 50% overlap until you get past the butyl tape. Then reverse direction and wrap back up to the antenna base. Resist the urge to pull on the tape to break it. Use scissors or a razor blade. When you stretch the tape too much, the plastic stretches and thins out the adhesive. That's where it'll start to unravel.
If you really want to go hardcore, follow all that up with a cote of Scotch "Scotchkote".
That's the method you'll see used at commercial sites. Having done it this way for a long time, I've never had a connection leak. I've pulled old antennas down and dissected the connector and found no water intrusion after 20 years of installation.
Yes, it's a pain. But it works. You can save money by doing a half way job, and it may work, or it may fail and you'll end up having to not only replace the connectors, but likely the coaxial cable, too. No doubt you'll get some hams that claim they never waterproof connections and they've never had an issue, but that's usually just someone confusing luck with skill. For braided coaxial cable, any water intrusion will result in that water wicking down the cable. The water and copper will corrode and make a mess. You'll not only damage the connector on the coax, but likely several feet of coax. The corrosion can also damage the connector on the antenna.
You can purchase a kit like this and get what you need to do several connections:
https://www.theantennafarm.com/catalog/commscope-221213-1956
If you keep your eyes open on e-Bay, you can often find those kits even cheaper.