Since you don’t have crown molding, you may want to raise the rod and buy longer curtains. I prefer the blackouts close to the window to prevent the heat from coming in during the summer and cold in the winter. Use round clips on the curtains to eliminate the granny look and buy a fun set of sheers that are your style. I have some that have polka dots, others with crisp modern lines. Check “Exclusive Fabrics sheers“ on Overstock— nice quality and inexpensive. Also, look for the NICETOWN blackouts on Amazon. I have about 10 sets of them. They are fantastic.

there are many curtains that aren't dated at all!

check out West Elm and CB2. they have thick curtains that have a kind of pocket that makes them fold up nicely when opened rather than being all scrunched up like the old style (hidden tab top). for example: https://www.westelm.com/products/textured-upholstery-velvet-curtain-regal-blue-t4353/?pkey=cwindow-treatments

I don't think you need to raise your curtain rod if you don't want to (or can't), but it would look better if the sheers touched the floor. you could do that by letting them out or getting new ones. sheers are cheap!

Sheers should be triple the width of the space that they cover. Those are twice, if that. I agree that using clip rings would update the look. JudyG Designs hit the nail on the head.

Full drapes across will be expensive. I'd put non-sheer drapes on the side as stationary panels, then add a roller blind if needed.

Twice the width is acceptable & I think they look ok to me-- I was really trying not to purchase new sheers & rods due to budget constraints.

I posted some suggestions from more expensive stores, but many places have them. just google "hidden tab top" curtains. I've had good luck with curtains from Target, for example. And I think Ikea has hidden tab top as well.

velvet is thick and will be room darkening -- so they'll let a slight amount of light through. then of course blackout is what it says it is: blackout. but the cheaper blackout curtains (like from walmart) have a plastic backing that looks kind of bad. as long as you don't look at the backs it's ok!

I am not suggesting new sheers or new rods. The sheers don't need to be behind the stationary panels, so when you add the stationary panels to the sides on the front rod, just push the existing sheers closer together on the back rod for more fullness. Adding the clip rings to the existing sheers, on the same rod, is optional but would look good. They're very inexpensive at Ikea.

IKEA rivta are beautiful and super affordable! $29 per pair!!

These are the sheers/stationary room darkening panels. The only issue i see is that the side drapes will have to be pushed past the "support hooks" in the middle---doable, but not ideal.

if you got stronger rods, you could get away with one support in the middle. but you said this is a rental, so I'm not sure if you want to deal with all that.

I used to do things like this and found that landlords either don't notice, or are happy to get the upgrade (I do a good job so that helps).

EDIT: looking at this photo, you might be able to try one middle support with the rods you already have. you could always move it back to the way it was if it doesn't work. patching holes is easy.

D. Stone is the landlord, not the tenant.