Well, I think the best way to welcome a new user is to help the user get used to using of tags since what he or she will be doing is to make posts and the right tag must be used. Here is a post I wrote on use of tags which will be helpful to all
https://steemit.com/redfishpillar/@camillius/what-a-minnow-should-know-use-of-tags.
Also there is the need to upvote and comment on the posts of the new user so that he or she will feel loved and will not backslide. I have seen people leave steemit just because they were not getting the upvotes they wanted. So the new users should be well curated and a proper guideline is to be given them on how to write a good post.
They should also be taught the following
How to get known and attract more followers most especially whales
How to upload videos on either Dtube or YouTube
To comment on people's posts
To upvote the posts of others.

There is also the need to introduce the new users to different groups and different chat zones both on steemitchat and also on discord

New users should also be taught the need to participate in contests as this will help them in a very long way