Best sealants etc

[swampydrill]

I'm going to be doing a few jobs around the house and would like to know what people use when doing plumbing jobs.

Waste pipes under the sink, they have rubber seals on them but do you put anything on the threads of the joints.

Water pipes, both hot and cold, will be using 15mm compression fittings, just use PTFE tape ?

 

[Madrab]

No need for anything on new fittings or plastic. If re-using compression fitting and olives then a couple of wraps of tape over the olive won't hurt. Reusing the plastic then a new seal depending on the old ones condition.