Depends on what you can afford & what you want to do.

If you are just doing them for fun, it doesn't really matter, but get a good quality oil from someone who knows WHAT they are selling.

If you are doing them for aromatherapy, essential oils are what you need, as they are what work on/with the limbic system of the body. They are more expensive, but you also use less of them. And not ALL scents are available as essential oils.

Hazel

Thank you, Hazel. I'd like to make soap to give as stocking fillers so I'd like to have a nice, lasting scent for the soaps. I guess I'll go with frangrance oils. Any advice about shea butter? Refined or not?

I think fragrance oils have longer staying power in M&P soap than essential oils. Essential oils seem to fade after a bit. As for the shea, I have used both unrefined and refined and I (and my customers) prefer the unrefined. It has an odor to it, but the odor doesn't stay on your skin. The unrefined shea has healing properties that the refined shea loses in the process of refining. Refined shea is white and creamy, like a thick lotion. Unrefined shea is a grayish-green and is chunky. If you want to add shea butter for maximum skin benefits and healing properties, use unrefined shea. If you just want the moisturizing properties, you can use refined shea.
Susan

Susan, thanks for the info. So many choices and decisions. I hope my finished products are worth the time and trouble.

I recently purchased concentrated fragrance oil by Elegant Expressions at Walmart & I wanted to know is it safe to use that when I make candles?

Personally, I prefer essential oils for soaps. They are plant extracts, so naturally, they smell like the real thing. As for fragrance oils, they are better for candles, as EO'rarely work well in candles. Some FO's are good for both candles and soap, but some are not. So you have to read the label for each one.

Within the essential oils, some may last longer than others. For example; a spice EO (using half the amount) will outlast most citrus oils. So it depends on which oils you want to use.

A good FO should be formulated to last made by a reputable manufacture. If I am looking to use a citrus, I would consider an FO rather than an EO.

A tip: Note the flash point of the oil (EO or FO). EOs with flashpoints less than 150F don't hold well in cp soap. Citrus oils flash at around 110 F which is why they "fade". "10x" citrus oils have better staying power, but be aware of amounts, as they can be irritating to sensitive skin.

Most FOs have flash points around 200 F. Since oils with higher flash points have to be ground-shipped, most companies will list the flash points somewhere on their website. Otherwise, you can you can find the info on flash points on the Manufacturer's Safety Data Sheet. Hope this helps