I had to make a smoke machine for a staff so I thought I would take pictures along the way! I did forget an important step... After you solder the positive and negative to the clearomizer you need to insert a small tube into the clearmizer bottom. This helps direct the air from the fish pump. Each image has text to follow along to. I've included the links to where I get my materials below. Things like the clearomizers you can buy anywhere but I just included my preferred store. Same with Fish Pumps.
Small board: https://www.adafruit.com/product/1862
Switch: (I actually forgot where I got the one in the photo but I'm a huge fan of this button) https://www.adafruit.com/product/1092
Battery: https://www.adafruit.com/product/1781 (I'm a fan of this one but you can use any of the rechargeable batteries on adafruit's site, just make sure it's on the higher mAh end.
I hope you enjoy this little write up! I do like making these so I will take commissions to make them if you ever want one. Please just give me a while since batteries take time to ship.