Resin and wood ring

This question comes from Sam:

Hi there, I’ve recently stumbled across a selection of wood/resin rings (a la Secret Wood) and would love to attempt creating one for my Mother’s 60th birthday. She absolutely loves crafting and is forever creating beautiful bits and bobs for me and my partner – so I would be thrilled to make something for her for once. I’ve got experience in working with wood, so that won’t be an issue, but I’m an absolute novice when it comes to resin. Would you be able to provide advice on what mixture I should be using? I’d ideally like to attempt something ‘fairly simple’ such as this: http://laughingsquid.com/wp-content/uploads/2016/04/Rocky-Lagoon.jpg?w=750 If my first few attempts go well, I’d like to look into adding some colour details/smoky swirls into the mix as well. Any help would be immensely appreciated. Thank you! Sam