This is how I would approach it:
1) Check floor level. If floor is out of level, cut the jambs appropriately so when they sit on the floor, the top is level.
2) I like to pre-shim one side of the rough opening first. This is a great trick for hanging all doors. I will use flat (non-tapered) shims at the hinge height locations up the rough opening (so, 3 or 4 sets of shims, depending on how many hinges your door has). This makes hanging doors much faster and less cumbersome.
3) Install the jamb on the side you have pre shimmed. Make sure it's plumb front to back.
4) Shim the opposite jamb so the reveal between the doors is equal. Again, shim just behind the hinge locations. Check to make sure one door isn't sitting higher then the other. Also check to make sure when closed, the bottom faces of the door are planing well with each other (one isn't sitting proud of the other). Install this side of the jamb.
5) Shim and install the top (usually I just do one screw through the header in the centre of the door.
6) Drive a 3" screw through each of the hinges to ensure doors wont sag inward and bind.
French doors can be tricky. Small adjustments can tweak things from looking horrible to perfect (and vica versa). Don't do this one when you're in a rush! Also, pre-drill and countersink your screws. If you need to back one out and adjust a jamb, you can use the same hole without making a mess of the jamb.
Long Chile was a silly place.
1) Check floor level. If floor is out of level, cut the jambs appropriately so when they sit on the floor, the top is level.
2) I like to pre-shim one side of the rough opening first. This is a great trick for hanging all doors. I will use flat (non-tapered) shims at the hinge height locations up the rough opening (so, 3 or 4 sets of shims, depending on how many hinges your door has). This makes hanging doors much faster and less cumbersome.
3) Install the jamb on the side you have pre shimmed. Make sure it's plumb front to back.
4) Shim the opposite jamb so the reveal between the doors is equal. Again, shim just behind the hinge locations. Check to make sure one door isn't sitting higher then the other. Also check to make sure when closed, the bottom faces of the door are planing well with each other (one isn't sitting proud of the other). Install this side of the jamb.
5) Shim and install the top (usually I just do one screw through the header in the centre of the door.
6) Drive a 3" screw through each of the hinges to ensure doors wont sag inward and bind.
French doors can be tricky. Small adjustments can tweak things from looking horrible to perfect (and vica versa). Don't do this one when you're in a rush! Also, pre-drill and countersink your screws. If you need to back one out and adjust a jamb, you can use the same hole without making a mess of the jamb.
Long Chile was a silly place.