Choosing a username can be tricky nowadays.
What you ideally would like to use may already be taken. This is very frustrating for students. My daughter has been begging me to permit her on Instagram. I'm a rule follower, so I keep telling her to wait until she is 13 yrs-old, the age permitted on the Instagram policy, and recommended by Commonsensemedia.org.
Months and months of, "Everyone else is on Instagram! You don't trust me!" Well, this is another conversation... Now that I do feel she is ready, we've spent days thinking and talking about the best username. Something cute, that reflects her personality, but that will be short so peers can find her. The parental voice coming out, "No, you cannot be 'cupcakelover'!" The word lover anywhere in username makes one a target for sexual solicitation. Everyone knows that 12-17 year-olds are targets for sexual solicitation by the age group of 18-25 year-olds (thank you, commonsensemedia.org), because they are curious and vulnerable.
What does make a good username?
One can create a username based upon the online tool. For example, I use betweenthewires when I assume the role of being a community service provider about technology integration. At work, I'm kboswell. As a mom, I'm also kboswell, but kboswell2, because kboswell was already taken, and I'm 2nd in command at the Boswell household. I found an article that addresses the audience of one searching to brand oneself. It seems that moving back to just your name, instead of 'handle' is becoming more popular. We are more mature as digital citizens, (How to pick a good username, @eschmidt0).
Another site called reputation.com (How to Pick the Right Username), also toot the horn of using your real name, but if it's not available--be professional. Don't pick a name that is vulgar or offensive. Here's where you, the educator, the adult, can help a student. They don't know connotation that well. It's not part of their thinking yet. We can simply explain how some words 'give a certain connotation or feeling'. For example, if I say 'poop', you have a negative connotation from this word --yucky, gross might even come to mind. If I say 'meadow', you might think --calm, peaceful, beautiful. We have to tell them that 'lover' or 'kimxoxo' give off a sexual connotation that might attract unwanted attention. Now, if the child is too young for this conversation, maybe they shouldn't be online at all. Because the reality is this...newspapers and television of 'the day' even follow a certain protocol to keep viewers, to maintain a family reputation.
The internet doesn't follow protocol. We have to be mindful watchers and protectors of future.
