Newsflash: paint is sticky when wet. Hours of hard work can be destroyed by a single thumbprint, and most people know not to touch wet paint. What’s less obvious however, is the risk posed by tiny particles of dirt and dust in the air. Hair, dirt, dust, and more will completely ruin a nice flat paint job. Glossy paint especially will highlight even the smallest imperfection. Unless you are doing a heavy weathered look, it is vital to protect fresh paint from sources of contamination.
To keep your hard work safe, you must shield tacky and wet paint from air currents. Fans, wind, air conditioning, and even tiny gusts from a closing door or a moving body can all deposit filth onto your work. This problem is so pervasive that professional auto painters will even wet the floor of their paint studio before shooting paint, just to make sure any residual dust that was tracked into the work area is immobilized on the floor.
I recommend painting in a ventilated, but sheltered location. A garage with a partially opened door works well for this. After applying the paint, find a safe spot for the piece to dry. You can seal up the garage, or carefully carry the piece to somewhere calm in your home. I have found that laundry rooms and bathrooms are a good option, as long as there isn’t an active A/C vent blowing into them. Closing the door to these small rooms will isolate the paint job from any outside air currents (as well as pets and people), and the ventilation fans will gently remove any released fumes without creating large air currents.
…and for the love of God don’t blow a fan onto the paint to make it dry faster