First of all I use Miracle grow potting soil......not the moisture retentive type....just the plain old potting soil. It is as sterile as you will find in my opinion, holds moisture well and drains fairly well too. I use 5oz. plastic cups which are really inexpensive and I drill 3 small holes in each for drainage. Then I put the soil in, tamp it down well and make one or two holes in each cup for the stems of the plants.
I take cuttings from semi-green stems. In other words stems that are green and have not hardened off yet.
I cut a stem off at about 5 or 6" that has enough leaves/nodes on it that I can take the bottom 3 leaves off. I actually pull them off against the grain to injure them to some extent. This is where the roots will come from so don't snip them, pull them off.
BTW, the cut to remove them from the plant must be as clean as possible so use sharp scissors. Don't pinch......cut. After I remove the 3 leaves I dip the stem in rooting hormone powder deep enough for it to cling to all three nodes and then gently tap the stem on the inside of the bottle to knock off exess powder.
Then I gently place each stem(do one stem at a time) into the prepared hole in the soil and press the soil in around it firmly but gently. Now I'm ready for the next stem.
The secret to success is moist but not wet soil and then moist but not air around them while they root. I use old aquariums with glass tops to hold the humidity level, and place them in in-direct light so they don't get too hot, checking every few days to see if they need a misting or not. They will root in less than 3 weeks if all is well and I wait to see some new growth. When I do I gently pick them up by the cup and look for roots through the walls of the cup.
Patience is critical. They need to be left alone. Don't move the stems.
A good guide for me is if the top leaves are clinging to the stem. If they defoliate it usually is not a good sign but they can fool you so wait at least 3 weeks to a month.
If you don't have an aquarium you can put them in a tray and put plastic wrap over them to retain moisture. The leaves/needles need to be kept humid while the roots develop.
One other thing. I use those Shish Kabob sticks (sp.?) they sell in the food stores to make the holes in the soil. I find a million uses for those things.
I also clean the roots of soil with them when repotting the trees. They can also be used to prop up the plastic wrap over the pans you place your cuttings in.
I hope this helps. I know it sounds involved but once you develop a system it becomes like second nature. I really enjoy doing it. Seeing little Elm or Maple trees 5" high getting a start is one of the most fun parts of the hobby for me.
(also my very 1st tree). Not worth trying to force a tree to grow under conditions it doesn't like!! But being new to bonsai I've got many experiments ahead!! I'm also interested in trying powderpuff & pomegranate (in time, ill know their genus/cultivar names, excuse me !) basically they all my trees are sub or tropical at this point. I've got a S facing window that opens to a flat area 6ft x 4ft. It's not a deck, rather the roof of the apt below but, I want the husband to help me make a wooden perimeter so they can summer vaca w/o worry about blowing off & falling 3 stories!!