This is a little vague... As this greatly impacts the topology, do you have any specs this VCO must conform to? But as a general statement, just look up ring oscillators and LC oscillators to understand them first, then choose whichever one you feel will meet the requirements.
I have the most basic design, I have certain requirements, only to be for a frequency of 1GHZ, beyond that I will alone get varactor etc. to control the width of the bandwith
Well, if you wish to use the varactor for tuning, then simply use an LC oscillator, or a colpitts. It is best if you have some model for the varactor, so you can scale it accordingly to match calculations.