Since your question seemed to be particularly about transfer from PRIMARY to SECONDARY, what I (used to) do is use a section of women's panty hose (long enought to not "fill up") attached to the racking cane or on the tubing coming off of your spigot on your fermenter. It catches the majority of the crud, and really does clean things up.
Naturally youwant to sanitize the hoisery first, but it does a great job.
Having said that, many here have stated, and I agree, that leaving the beer on the yeast cake and trub actually adds to the "complexity" of the beer. In other words, no need to use a secondary at all. Just let sit in primary for some extra time.
I use this method with my stainless conical, and unless you have concerns about keeping the outside elements out of the primary, there really is no NEED to secondary, but it is a matter of choice.