For all new Cogent TYPE-C™ HPLC columns with the exception of new Diamond Hydride™ columns, all one needs to do is run 7-10 column bed volumes of your mobile phase through the column at your normal flow rate. Then it is best to inject a known standard and repeat the injections until duplicate chromatograms are achieved. You should be able to achieve this within 2 to 4 injections. Often chromatographers will use the analytes used in the test chromatogram supplied with each column.
In addition, a new Cogent Diamond Hydride™ column should be conditioned as follows: Flush the new column overnight at a low flow rate (0.1 mL/min) with 50:50 MeOH/water. Then in the morning, switch to whatever mobile phase you want to use and let the system equilibrate for 30 min before starting your runs (here you would use whatever flow rate your method calls for). This should bring the column to a state where it will run for many injections very reproducibly.
The only exception to this is where acid and ammonium additives were used on the same column. We recommend that if you want to use both types of buffers, you should have two columns.
Related article: Conditioning the Diamond Hydride column for serum samples