How can a new profile be created?

There is a shell script to create one in the doc/devtools directory (only included within CVS checkouts, i.e. .tar.gz files don't have it).

Basically create a blank database, go through your admin settings and then run the script.

Step by step

Before starting, you should decide on a short name for the file and also a somewhat longer description of the profile. You will also need to define what features, groups, and group permissions you want to include. A good practice would be to create this info as a wiki page here on tikiwiki.org and then when you are finished and it is uploaded to cvs, you just link the page describing your profile into Using profiles where they are documented.

Prepare a Tiki instance as a reference point. This can be a new install where you configure all the needed feature as and groups, or an existing site that you want to model the profile after.
Perform a mysql dump of the refernece site's DB
cd db/profiles
./mk_profile.sh <dumpfile name> <profile name>
Edit the resulting .prf file to remove personal, inaccurate or un-needed inserts, e.g. 'feature_server_name', 'cookie_path' and 'cookie_domain'. Change the comment on the first line to have a better description.
Test your new profile. It will show up automatically if it is in the db/profiles dir and has an extension of prf.
Document in Wiki page linked to Using profiles
Upload prf file to CVS