I would say there is a big difference between making products for yourself and making products for use on clients (and to sell to clients).
If you are making them for yourself then it can be a bit of fun and will give you a better idea of ingredients, how cosmetics work and you will have something you can tailor to your skin type.
If you are making it for others (even give aways) then you and your products will have to adhere to the Cosmetic Products (Safety) Regulations
The Cosmetic Products (Safety) Regulations 2008 This covers all the requirements needed. You will need safety assessments for each product, a PIP file, and ideally have product liability insurance. Each product needs to be correctly labelled in accordance with the above guidelines and weights and measures guidelines. Each product will require batch numbering, micro and you to keep a retained sample.
Out of the items I mentioned above the insurance would be one of the toughest as it is costly (we pay over £5k a year). You can do it without but then any problems would be at your expense. Safety assessments do also cost, budget between £250-£1000 per product depending on how complex the product is. Micro will be about £50-80 per product per batch.
If you want some more information then just ask.