Ideas to section off?

If one were growing in a closet type situation... what is a easy and effective way to separate 2 areas? One side for veg and one side for flower. Also need to consider how to make sure both sides are breathing properly...

Insulation board like this is cheap and easy to work with, if this is the type of thing you are looking for.

http://www.lowes.com/pd_15328-46086-15328_4294858106__?productId=3582748&Ns=p_product_qty_sales_dollar|1&pl=1&currentURL=%3FNs%3Dp_product_qty_sales_dollar%7C1&facetInfo=

be really careful about light leak!
anything leaking from veg and shining on the flowering section will cause you major problems..
(same with little operating lights on fans and humidifiers...cover with dark tape)

insulation board could work well...
so would big sheets of corrugated polyurethane... usually separates levels of pallets in warehouse work.

stuff like that is going to be great for you because you will be able to easily cut your holes for air exchange and heat evac.

Your only issue is light leakage, I highly recommend using two sheets of panda film. It's cheap, one of the highest reflective substances (much better than mylar) and doesn't create hot spots. I'm a big fan of panda film ever since I discovered it, use it with my veg room directly next to the flower room.

2 layers of 3/4" Mylar coated white poly styrene foam board. Use liquid nails to adhere the edges of the foam board to the floor, ceiling and wall. Make 6 strips of moulding from the foam board ( about 1-1/2" thick) to trim and lightproof the edges where the foam board is glued to the drywall and floor .

add in a filter black speaker felt to a fan in the middle of the borad one side is the intake one is the exhust and the missle pass it to the exhust side ....the double side speaker felt should aborb the light so no cross over

How big is the closet?

Considering all suggestions to best suit...

4x9 with a slopped ceiling... kinda like a staircase closet. Short wall is 3' and the tall is 7

LOL I grew in something almost exactly like that at one point, dimensions and everything. I put a broken dresser in the closet and stored my mothers and babies in there, flowered in the rest of it. Skirt off the lower area with about 3 X 4 feet of horizontal space, or 2 X 4 if you feel you can manage it. You don't need a wealth of space for your veg room, unless you're trying to do a perpetual or something fancy like that. As far as the room breathing properly, tape speaker cover over either side of a very small fan and put that in one corner of the space which will be taped off as the veg area, as your intake. Exhaust depends on how you plan to light them, but with small fluorescents as you likely plan to use there may be no need. As for the actual wall itself between the two, use panda film or reflective insulation board or one glued on to the other to ensure absolute light isolation so that the flowering room is not affected. Hope this helps.

I guess in some sense, I am doing a perpetual... want clones that have been pulled from the flower room to go into a veg room. Figure I can have a few zips, every few months with 4 plants.

So I know that you want zero light shining at the flowering plants, but what if you have just a little glow around some edges or whatever? I just need to get something in place now because I'm outta time... I can improve later. Its a stealth deal so its been tuff to actually be able to get in and get it done.

I was warned early in my growing career to even foil-tape over any buttons in the room that are illuminated when on, for instance my radiator... so that should tell you how concerned growers are about affecting the flowering cycle with loose light. I would caution against it, however it's up to you. If you really feel you can't get in there and put in the work, then it's frankly not really worth discussion though, is it?