I'm an all of the above kinda guy. My wife had no interest in her g-spot and little interest in sex at all. My motivation was that if she enjoyed it more - she would want to do it more. After 22+ years I can report moderate success!
Back to the g-spot. After reading about it - I turned the more or less normal act of fingering her during foreplay it to a purposeful search for her g-spot. So using the classic come-hither stroking of the top of her vagina and combining it with some oral action on her clitoris - we found it!
A lot of the battle is finding it. In my opinion you should be somewhat aroused before even probing. It seems that the g-spot is erectile tissue that enlarges with increased blood flow to the genitalia.
It was quite sometime before finding it - lead to anything more than mildly pleasant sensations for her. There may be a feeling of needing to urinate that you have to get over - this happens because the g-spot surrounds the urethra and when it engorges it puts some pressure on the urethra. But you have voided before getting started - things will be OK.
What we find most effective for delivering combined orgasms - those that involve the vagina and clitoris are a combination of a dildo and a clit vibe like Mimi or Mystic Wand.
For the penetrator her current favorites are:
Pure Wand, VixSkin Johnny, G4 Big Boss, Mona and occasionally a rabbit toy like Decadent Indulgence.
Most off all - don't try too hard, keep a sense of humor, be patient and enjoy the journey!