The English manufacturer of YG describes the process for using it is a series of steps:
- Sand the piece to 320 grit
- Apply one (or more ) coat of sanding sealer. My sense is that in the UK, lacquer-based sanding sealers (also called 'cellulose sealer') are more popular than a shellac-based sealer.
- Use YG to polish the surface
- Apply a final coat of wax such as Hampshire Sheen or Chestnut WoodWax 22, or a microcrystalline wax
In this sequence, the use of YG is essentially the same a buffing with a wheel and buffing compound - that is, it is used to polish an underlying finish, and before a wax top coat is applied. That is, the sanding sealer is the actual finish, and the YG and wax polishes the surface to a gloss. However, you will also see people who apply YG to raw (unsealed wood); in this approach, the true finish is just the wax - that's OK for a display item, but it won't withstand a lot of handling, and many turners in North America assert that wax is not actually a finish, but rather only a surface treatment. And there are a few people who suggest using the YG to polish the raw wood, and then applying a danish oil as a top coat.
There are other products that are essentially similar to YG - the Australian Shellawax EEE, and the US Dr. Kirk's ScratchFrEEE for example. And there are formulas for DIY versions that are variously referred to as polishing wax or sanding wax ; these are typically blends of beeswax, mineral oil, and an abrasive such as pumice or diatomaceous earth.
My most common 'go-to' finish is a long-oil varnish that produces a nice soft-gloss surface. If I want something more glossy, I can either break out the buffing wheels, or use Dr. Kirk's ScratchFrEEE. My unscientific observation is that either approach produces a nice initial gloss, but the carnauba wax final step with buffing wheels is longer lasting.
Different strokes for different folks.