Biggest tip I can give is to find/make a room/space where there is little to no background noise & as little in the way of ambient room reflections as possible.
Essentially you want the closest, warmest vocal sound that you can get, not just so that it sounds ‘pro’ but also because of psychoacoustics; the more the brain has to work to filter out background sounds and reflections the more strenuous and tiresome it is for the listener to stay focused.
Most people think that the key with this is having a pro mic but actually the acoustic qualities of your recording space are just as, if not more, important. A cheap mic in a well treated space is going to always sound way better than an expensive mic in an echoey or noisy space.
Having said all that actual concrete tips on how to work your recording environment depend very much on the type of recordings you plan to do. Always one voice (yours) recorded at home? Interviews with others? (ie recording with more than one mic at a time, phone or Skype interviews?) Vox pops on the street?
They all require different approaches/tools/planning