Well it depends on the type of piping design you will make. Are you using R2001 with the Spec-Driven Option? or the earlier releases?
Basically they both have the same results, but the Spec-Driven Option allows for faster creation of large scale piping projects.
If you are making "manageable" piping assemblies, always start your new pipe at the assembly level it is to reside in. So now all your reference points will be linked to that assembly level.
In this assembly, create the references for your pipe paths, such as assembly-level datum points for the start, end and all transition pionts of the pipe.
Next you will need to make the Linestocks (standard pipes, hoses...define you pipes well here, this is the real trick), then start building the pipe path using the previously defined reference points.
After you made the pipe paths, then you can add the solid pipe geometry and then the fittings.
Of course it's a bit more than this, but following these logical steps will save you much time.
Steve