Come up with how you want to identify the recording artist in the catalog number. Sometimes labels use letters or abbreviations to identify the artist. For example you might choose to use the band name initials, or part of the name, or a series of letters like "XRS" that will appear on every album the artist releases.
Come up with a numbering system. The numbering system could be simple, to mark the CD as it appears in your label's line of releases. For example if one band releases a CD and the next number up is 345, and another band releases a CD next, you'd have 345 followed by 346. Note that you can start at any number or add additional digits to signify both the overall label number of albums currently and the bands. For example TFB-34502 might signify the 345 album released on the label and the 02 as the second album on your label for the band identified by the label as TFB.
Combine the letter and numbering system and keep a record of it. You may choose to keep a running spreadsheet record on a computer so you don't duplicate release CD catalog numbers.
Include the catalog number on the CD release, whether it is on the case, in the booklet, on the CD itself or a digital copy embedded in the ID3 tag or digital booklet of the release.