Have been the towing vessel several times ranging from a Catalina 22 towing about a 30' powerboat (talk about embarrassing) to a 45' sailboat towing a similar size sailboat for a couple days offshore (no wind, no engine).
Echo the advice given above. If you're not comfortable, don't do it. If you choose to, be very, very careful. Some of the things we did that worked:
- use an anchor rode as a tow line. Nice and long and stretchy so will absorb a lot of shock without overloading attachment points.
- use a towing bridle on both ends. a bridle is much safer to release than trying to untension the line to get it free. That way either vessel can abort the tow if something goes awry. Mooring lines with chafing gear make fine bridles.
- if steerage is a problem (busted rudder), consider a small sea anchor off the stern of the towed vessel to keep them inline
- use the towed vessels line
- agree on hand signals, and establish/maintain vhf contact
- allow no one anywhere near the bridle! If something gives way, let it go. Line is cheap, an arm or leg is not
- slow and steady. No reason to hurry. Otherwise you end up with 2 boats needing rescue!