Simply meditating on your third eye works, and it works for me if I say some mantra while in meditation. I also believe a tea of mullein, coltsfoot and mugwort help.
It can take a while to see orbs/spirits, but it isn't impossible, you simply have to put your mind on the fact that there are spirits among us, and that you want to see them. Once you have this mind set, this belief, then you'll start to see spirits. Meditation does help.
Generally, in my experience it helps if the room has a lot of energy built up already. You can do this by playing music that you enjoy, either it be dark or just full of some sort of energy. Chances are that there'll be more spirits present. To get dark orbs to come, and you may feel drained and depressed if you bring black orbs into your presence, just play dark music and sing along with it.
Or you can get into a heated discussion with an enemy and notice to watch for at least one black orb to buzz around.
Kind of fun playing with different energies, but the black ones can make others depressed and drained. The white orbs I don't know what to make of, but I've seen them circle me one time while going for a run. I'll call them nature spirits, because they seem to be the only thing natural.
Understanding the invisible waves and radiations from candles will definitely help with seeing/understanding spirits
Think of the essence of a candle as a dry-point, a destroyer of moisture.
Think of a candle as a switch; the flame is on.
The dry point and heat in a still candle, heat the air and elevate it.
The moist cool vapor is drawn towards where moisture was drained; by understanding this, one can gradually see invisible candle auras, understand the candle color effects, dry things by knowing where to place the item (not so much above the candle so much as to its side)
When I just started to lurn how to do that I put a small pice of clear quartz behind my ear and toned my energy to it, clear quartz is like a universal use crystal cause it just emps everything and picks up any energy and spirits put of energy, so if you do this right than you should be able to see them
Get a pack of sage insence as well as one the color of each element. A bowl of dress dirt. Form a pentagram with the element sticks with each element being in the proper place. Purple(spirit) at point an clockwise being brow or green(earth), blue(water), redor orange(fire), and yellow(air). Place the sage in the center. Cast your circle, light the insence one by one clockwise. Sage last. You should see them if you also place a bit of clairvoyance oil on your brow as well. Research on oils and find one that's suits your liking. If u don't use the oil, you will still sense the spirits.
Candle meditation does help greatly in my experience. Especially for beginners. It is an easy way to focus your energy and concentrate on seeing the energy of the candle. Like the previous person said see the aura around the candle and once you get good at that try doing the same thing on people or animals or whatever's you choose.