Wipe down the space you plan to use for your altar. If you are using a temporary or travel altar, you can give it a little wipe down unless it is new in which case it doesn't really need it. Once it is actually clean, the first true step to preparing a space for consecration is to actually cleanse the space. I usually like to use two different tools: one to wipe down or cleanse the actual table and another to spiritually cleanse the space around the table. I usually choose a spiritual cologne for the table and a smoke wand or incense for the space around. Do and use what works best for you.
Before we begin, I want you to choose either a prayer, an affirmation, or an incantation of sorts that you can say while you do this next process. Choose something that will help you prepare the altar for its use. I like to say a general statement to my spirits and occasionally a prayer. Once you have chosen what you will say, put a tiny bit of magical oil on your fingertip preferably something linked to power, protection, or spirit work. Starting at the top left corner, say the prayer and form a small cross on the corner. Do this for each corner of the table until you return to where you began. If you do not want to use a cross you can simple dot the corner.
Now you are going to grab your candle and some chosen herbs/resin. You do not need much, sometimes working with only one herb/resin is best. You are going to prepare a candle for consecration. If you need a recap on how to dress a novena candle you can review the blog post on the realm. Once this candle is dressed, you are going to place it in a candle holder or in a fire safe container, and then place that in the center of the altar space. Once you have done this, you will light the candle and let it burn to completion.
Now that the space or the table is consecrated, you can take the items you chose for your altar and place it on the space. Feel free to add other items if you wish. I will guide you to add a few other items during this journey. Make this your own and do what helps you bring this space alive.