It's self-evident that manners and respect are always required on this forum.
Many of the contributors post on this forum and even more read it. When you comment on a contributor, if it's a recent folio (1-2 months) she is likely to read it so please address her directly. e.g. "I really love your eyes" rather than "She has really lovely eyes". It is OK to discuss contributors in the third person for older folios if they aren't currently active on the Forum.
This is not a porn site so please don't use porn vernacular. The contributors do like to be complimented and admired, but not fetishised.
"Great bod I love your nips" is not an appropriate way to speak to a contributor (aside from the bad grammar). Talk to people here in the same way you would if you were facing them personally. "You have a fantastic body and I especially like your nipples" is far better, but hopefully you have something deeper to say as well.
Requesting a contributor submit again is perfectly fine, however don't be demanding and don't ask them to reveal more or pose in ways to please you. You may have an idea for a shoot theme, that's fine, unless it involves doing "X" with "Y" for example (where Y may or may not be human!) One simple test is - if your post contains the word "should" then you should rethink it
Do not ask contributors to submit to other Feck sites. They know about them, and will contribute if they choose to.