My way of making smokeless incense blends is as follows:
I'll use a base plant. Fragrant plants such as rose petals, or lilac are good. You also could use an intent based plant for ritual incense such as goldenrod for money or luck.
After the base plant I'll use a couple drops of fragrance oil either one alone or a combination.
I may place these ingredients in an oil or wax warmer along with some scented wax if I choose.
An example of a fast money incense blend:
Eucalyptus fragrance oil.
Cinnamon or ginger fragrance oil.
You will add the goldenrod flower on top of the oil warmer, add in a few drops of each of the oils, and light a tea light candle to warm the oil warmer.
These smokeless blends can be used for multiple purposes. Two I currently use for purifying and exorcism.
There can be blends made for love, money, lust, etc.
They also need not be made entirely for intent. Some can be made simply for their fragrance. Say you are experimenting with blends and come across one that has a fragrance you enjoy, but you do not have intent in mind for it. This blend can then be used for a ritual or mood incense. A scent you use because of the mood it evokes.
Blends can be made for specific spirits or deities one works with as well.