I am going to try to save you some time from typing so much each time you welcome someone.
When you welcome someone for the first time, save your welcome once you put it in a comment box of the person your welcoming. If you use photos or GIFS this is especially important.
right click and copy your welcome before you click "add comment".
Right click anywhere on your desktop so you can make a text document and save it.
Paste the message and embedding code for animations into that text document and save it.
So now the next time when you want to welcome a lot of new people.
Just copy the text and paste from that file! TA DA!!
Its that easy.
Hope this helps :D