I use 6cm (2¼ inch) pots with seed/cutting compost and keep them in a temperature regulated propagator, I keep the vents open slightly and a pen wedges between the lid and the base.
If they start to wilt I close the vents for a few hours until they recover; doing this keeps air circulating and helps to stop damping off (the slushy stems)
After three days I remove the dome and see if they wilt, if they do I then re-cover them and try again the next day; I believe this forces them to transpire which in turn forces them to root sooner.
Also the heated propagator is controlled by a central heating thermostat to keep an absolute stable temperature night and day; I found that adding the thermostat increased my success rate from about 80% to 100% and I believe it’s because the heated propagator prevented the nighttime temperatures from going too low and allow damping off to occur.
The propagator without the thermostat was too warm 90°F and actually made matters worse, so I decided to make it controllable and have it set to 80°F.
Another thing to remember with clones is the state of the donor; Nitrogen inhibits root development so don’t take clones after you just fed your plants, also take cutting from fresh flexible non woody parts which are high in sugars, and the longer the clone the better.
I believe auxins produced in the tip inhibit root growth and the further away from the tip your cut is, the lower the concentration of the root inhibiting auxins are.
I go by the rule of thumb cuts must be at least 100mm in length and 5mm in thickness.
I also believe most people probably over water their clones, so if it helps I use four pumps of a sprayer (4ml) with fresh tap water + IBA in each of my 6cm (2¼ inch) pots.
The only additives I use are rooting powder and Bcuzz root stimulator which I believe contains IBA (Indolebutyric Acid).
My clones normally callus in three days, and start to show roots between five to seven days, I leave them in the propagator for two weeks as I don’t have anywhere else to put them.