To condition your beer when kegging, we usually recommend to;

1. Rack your beer after primary fermentation has finished (5-10 days) into a secondary fermenter. 
2. Add 1 sachet of Mangrove Jack's Beer Finings to remove the yeast sediment or any proteins that have dropped to the bottom of the fermenter. Yeast sediment can add off flavours and additional protein can cause chill haze in your finished beer. Read more about chill haze here.
3. Leave for 2 days to clear, if you don't have a secondary fermenter add the finings to the fermenter you are using.
4. After the 2 days of clearing, you can condition your beer by transferring your beer to the keg and cool down to 4°C (39.2°F) for best results. Note: gasses dissolve easier in cold liquid.
5. Attach the CO2 and set to 12 psi, purge the keg via the relief valve in a few short bursts.
6. Let the keg sit at this pressure for 4-7 days before drinking. 

You can purchase beer finings here - Beer Finings