This is how I do it:

I bought unscented incense sticks. I found some on amazon.ca, and I am happy with the purchase. Here is a link to the sticks I bought: Click here (note: this is an affiliate link)

 Before I use them, I take them in my hands with positive intentions by giving thanks to the material, and the manufacturer.

I lay the incense stick on a safe surface, like a dish, a plastic cutting board, or some plastic foil.

I choose my essential oil, or I mix different oils. I personally like Sandalwood, Frankincense, or Patchouli.

I hold the bottle with the oil for a short moment in my hands to give gratitude.

Then I gently sprinkle the essential oil all over the stick, until it is all covered with essential oil.

During this process my intention is that this incense stick will help me for my spiritual cleansing. For example: May this incense stick help to transform the energy, and to bring Love and Light into the room.

When this is done, I put my stick in an incense stick holder, or glass, and let it dry. The stick needs to dry for a few hours, maybe overnight, but I personally never wait that long. I already used it after an hour.

I reuse the dripping that is left on the dish by simply dipping another unscented stick in the leftover oil. I actually do more than just one stick at a time, because I use a lot of them. I like to use them when I do a spiritual cleansing, or just simply in my daily life to brighten up the energy in the room.

Note: I included this information in the course: How to do a spiritual house Cleansing" as well.