that cutting you've got is pretty small...take larger ones so you have a good 1"+ of stem to throw down in the soil.
Cloning is pretty easy...
1) cut a 5"+ stem off...cut off the leaves at the nodes but leave the top node and one below its leaves intact
2) put cutting in a cup of water immediately after ^^
3) once you have all your cuttings taken and put in a cup of water take one out
4) scrape the bottom 1.5" of the stem's sides to just peel off the skin a bit
5) cut a 45-60 degree angle off the bottom of the cutting(so you take about .5" off the bottom leaving 1" of scraped section above)
6) since you are using gel just dip it in the gel to cover the 1" of scraped stem
7) poke a hole down in your soil about 1" deep and insert the cutting so the soil level is at least .5" above the scraped part
press the soil up against the stem
9) water it gently and put it under a humidity dome. You want the humidity around 80-90% or so...so you may need to raise one side a little bit of the dome to let out some of the humidity
At a minimum of a couple times a day raise your humidity dome to let in fresh air.
Do not use soil that has much for nutrients...its best to use seedling starting soil or a peat puck so it doesn't burn the stem and cause roots to not grow.
Mist gently with PH balanced water daily for the first weekish. The soil should be "moist" but not wet, so you probably don't need to water it.
Depending on how far into flowering the clones are taken they vary on how long it takes to grow roots...the earlier you take a cutting the better the chances of it making roots...
That should give you a good plan of action for cloning