Fog in Bangladesh is a sudden, freaky occurrence. It gets terrifying just outside the cities because everybody else uses the road like a game. And there are goats wandering the streets as if they are in a mid-life crisis.
The most important tips of riding in fog or any low visibility conditions: see and be seen. How?
Make yourself visible: Wear jackets with reflective strips on them. A lot of hardware stores and motorcycle accessory stores sell high visibility jackets. It's well worth the several hundred taka.
Low beams if you have it: Most modern bikes have high and low beams. Keep them low so that you see the road more clearly. High beams reflect off the moisture droplet in the air increasing the glare and making everything more difficult to spot. Avoid HID kits for winter or rain because the extra brightness causes excessive glare when reflecting off droplets. They make everything go blindingly white. AIm the lights low towards the ground.
The best lights? Yellow fog lights/bulbs. It's the color that is least stressful on the eyes and lights up everything evenly without unnecessary glare.
Remember: Fog lights aligned too high are a nuisance at best and quite dangerous at worst for other road users. Be responsible.