I've never had a g-spot orgasm....any advice?

But I would like to have one! I'm pretty dependent on clitoral stimulation that I never tried for a g-spot orgasm. I have gotten sort of close through fingering in the past. Any suggestions on how to achieve g-spot orgasms? Is manual stimulation or toy stimulation best for your first g-gasm? And also, which do you prefer better: clitoral or g-spot orgasm? Thanks!