Joinery method for this project?

I need to make a lightweight 4'x3'x2' rectangular frame out of 1.5"x1.5" poplar. What do you think would be the best way? Normally I'd go M&T but I just don't have the time. Pocketscrews? Dowels? Seems like an easy task but for some reason I'm drawing a blank on best way to proceed.

Is it for looks or for function? In a quick build, I tend to drill pilot holes and use external screws. For it to look nice, pocketscrews would work well and be quick.

It all depends on the look you're going for and the function, as Brian pointed out.

For shop drawer carcasses for instance, I just use pocket holes. You could also glue some half lap joints or some kind of drawer lock type router method.

For 1.5" I'd hesitate to use dowels; kinda little space. Half-lap is quick and strong so that would be my preference.

I would go with lap joints at the corners, they are easy to make and stronger than miters or butt joints. If you need a nice looking front, make a mitered lap joint.

Just in case I wasn't clear, it's a rectangular cube frame. 3way half-laps or mitered half-laps seem a little time-consuming, unless I am missing something (entirely possible!).

We understand it's a cube frame, but what is it going to be used for? Is it for furniture that's going to be on display where you'll see the joinery, or will it be in the shop? Who's going to see it?

Matt, it's just a frame which won't be visible and will support decorative panels (probably frame and panels), as well as a door to access the compartment. However, for ease of putting it together and taking it down, it needs to be relatively modular (the frame itself can be one piece). I haven't yet decided how exactly I will attach and take down those panels. So the joinery of the frame itself isn't going to show - pocketscrews would probably work well, but then those screws may start limiting where I can put the knockdown hardware to attach the decorative panels.

I gave the mitered half-laps some more thought, and they'd actually be pretty easy and not that time-consuming. I just don't have a good way of mortising rapidly which is why I ruled out M&T.

Thanks for the help!! :)

+1 on the lap joints... also I'd pin them with hand made dowels if possible. No way would they fail then.

I built something like that with pocket screws and glue.