Everyone that is not so familiar with crochet then the decrease will be a complicated part. If you do it wrong you will get a hole there. You can go a few ways to decrease with single crochet. The easiest way is to connect two single crochet. Alternatively, you can just skip the stitch.
We start with single crochet.
To make the work a little easier choose a thicker yarn and the fitting crochet hook.
1.Variation
Get the crochet hook into a stitch and get the yarn over.
Go with the hook into the next stitch and get the yarn over.
Now you have three loops on the hook.
Get the yarn and pull it through all three loops.
Done!
2.Variation
Go with the crochet hook in a stitch and get the yarn over.
Skip one stitch and go into the next stitch, yarn over.
Now you have two loops on the hook.
Pull the string now through both loops.
Done!
The disadvantage of the 2nd variation: you will get a little hole.