Trimming cannabis means removing the excess sugar leaves from the actual cannabis buds. 

When you grow a cannabis plant, it comes through like a flower with a bunch of excess leaves around it. These leaves are called fan leaves and sugar leaves. The fan leaves are the big cornhusk-like leaves that grow from the plant’s branches; the sugar leaves are the little leaves growing from your plant’s flowers.

Those leaves contain cannabinoids and terpenes, but you definitely don’t want to smoke them, especially the fan leaves. They’re extremely harsh on the smoke, and will make you cough up your lungs. Keep your lungs inside. You need those.

There are two types of cannabis trimming: wet trimming and dry trimming you can use Giro's scissors for. Once you harvest your plants they’ll be full of moisture and nutrients that they took up during the growth phase. You can trim them then, or you can allow them to dry and then trim them after.

The advantages of wet trimming: your buds dry quicker if your grow environment dictates the need, it’s easier to remove the sugar leaves, and you don’t have to find somewhere to hang the plants.

The disadvantages of wet trimming: it’s sticky and you’ll walk away from the trimming session absolutely coated in sticky weed oils.

The advantages of dry trimming: you are able to dry your plant for longer, in the proper environment, and the plants are a lot less sticky once they’ve dried, and the sticky resin glands called trichomes on them have hardened.

The disadvantages of dry trimming: you have to be a little bit more delicate with the buds to protect the hardened, volatile terpenes.

Whichever type of weed trimming you decide is purely based on personal preference and necessity. There is no right or wrong answer.