You can get free resources every few hours by going to your Town and tapping the resource producing areas. You can get some Zel and some Karma as well as materials for items like Cures, Seals and Ores.
You should invest some Karma into upgrading your Forest, River, Mountain and Farm in order to get better resources from them. All you need to do is log in and tap away and every little bit helps. For resources that you don't need, you can always go to the Item building and sell them for some extra Zel.