I have three atomizer for misting my plants. In one, I have Schultz 10-15-10 plant food and SuperThrive. I use this for clones that look rough and any plants that seem to exhibit deficiencies. In another I have straight up water for those days when my grow space hits 86 or higher and won't come down because Florida heat sucks. My last one is usually mixed with Grow Big and Big Bloom for foliar feeding. It is a weak mix and I use it sparingly on younger plants because if you start feeding them through the leaves, the root growth suffers. I may foliar feed twice a week.
Also, if I suspect PH problems, I'll foliar feed the 10-15-10 and SuperThrive to see if I can notice an immediate improvement. If I do see the plant perk up right away, I know it is salts or PH lock up. I rarely have to worry about that though now that I have a Milwaukee PH meter.
You should not foliar feed seedlings unless they look very poor, then use a week Superthrive mix. Generally, you shouldn't foliar feed until the plant is in it's 3rd week. When flowering, don't spray the buds directly, just the fan leaves. Make sure you mist top and bottoms of leaves. And get a good mister, not a spray bottle. You want to atomize the water.
caution: Raise lights and turn off fans before foliar feeding plants. water on a hot bulb will end with a shattered bulb and glass shards in your grow. Also do it before the lights come on, not in the middle of the light cycle as the water may cause the lights to burn your leaves.