I bought a linen Mossimo dress from Goodwill for $5 this summer. It is (was) a halter top, which I don't like, but it fits well and is an A-line shape and a lovely shade of green, all of which I do like. Bonus: the skirt is lined so I don't need to wear a slip, AND it has in-seam pockets.
The halter style signifies summer to me, and since this dress is solid color and fairly long, it should be able to be worn in colder months as well. I typically prefer base pieces that can be worn year-round with some smart layering, and halter tops don't really let you do that. Plus they're just kinda juvenile.
To make this dress more friendly for autumn and an office environment, I simply readjusted the straps so they laid over my shoulders and attached to the bodice at the back. I marked the new length they needed to be (with bobby pins--not as secure as pins but easier to use with one hand when you're your own dress form):
I snipped a little below this and folded the raw edges down into the strap...
Pinned them where they needed to go...
Then sewed them on, retracing the existing stitches along the back of the bodice.
I cut the scrap ends of the halter straps to make three belt loops.
Pressed them in so long edges met in the middle.
Placed them around the waist of the dress, folded down the short raw edges and top-stitched. (I act like this step was easy, but I in fact messed up so many times and actually threw my seam ripper in rage after my fourth time of accidentally catching a strap or something on the underside of my stitches).
Simple changes and yet so much better. Throw on a cardi and welcome to fall.