If you are expecting a posterior instability repair, place the initial posterior portal more lateral and superior than the standard portal so you can get a good angle on the glenoid. Place it in line with the lateral most aspect of the posterolateral aspect of the acromion and 1 cm distal to it.
PDS Suttle for Instability:
Pull PDS through the portal, leaving just a hand full and tie a single knot, 4cm away a double knot and 4cm away a loupe for the suture from the anchor. Leave as much length as possible after the loupe for wiggle room