My mind is churning for Christmas gift ideas. I like to add a personal touch to most of my gifts, it saves on the budget and I find people really appreciate your thought. Making your own bath oil is extremely easy and affordable. All you need is a small decorative container, oil and fragrence. Here are my suggestions for the oil:
Jojoba Oil - This mimics the skins natural sebum (oil) so it has excellent absorbtion qualities.
Grapeseed Oil - This is non allergenic and it dosen' leave a greasy feeling.
Castor Oil - You will find this in many make up products. It is soothing and protects the skin from harsh conditions (cold wind) so it would be a great protector for cold winter conditions.
Sweet Almond Oil - Great for all skin types, softens, sooths and reconditions skin.
Prices range from $2.00 to $7.00 for a 4 oz bottle with the castor oil being the cheapest. You then need an essential oil. These oils are what adds the fragrence to the bath oil. There are many to choose from but start simple with just 1 or 2 scents that you know you like. Here's a great site that has a listing of oils and a description of their scent, it also has information on what scents work well with each other.
Plan on using 1 drop of essential oil per 5ml of the carrier oil that you chose (jojoba, grapeseed, castor or almond). I'm sure your gift will be very well received :)
Oh, and don't forget to make some for yourself!