it is easy. just get a good spray bottle. walmart has them for like 6$ or something. get one that is measured (shows measurements on the side). some people use ferts there are tons of products you can buy, but i like to just use super thrive. i mix to 1/4 strength with RO water and srpay plant. for example when i water with Super Thrive, i use 1ml/gallon, so when i spray i use .25 ml/ gallon. there are a few tips to look out for when spraying your plants. be very careful when spraying anything around HID lights, water vapor can cause bulbs to EXPLODE. also be careful when spraying your plants under hid lights, the water droplet can magnify the light and cause spotting on the leaves. when spraying, make sure the mist is fairly fine and be sure to spray on the underside of the leaves as this is where the plant can take in more water. i like to put my plants in the bath tub and thoroughly spray them there, then put them under the lights to dry off and uptake the water. hope this helped.