Very, very chic.

You could always pull cognac, black, and white instead of the yellow...if that feel more "masculine". to you,

You are off to a good start. Maybe an arc lamp in the left corner and changing the verticals. If you have the space for a modern accent chair this would work.

How about a modern rug that adds a pop of color but ties in with the gray? What colors do you like? Here's some rug ideas. You'll need to do something different for the throws, perhaps to pick up the rug color (orange or blue). I'm not that crazy about the artwork. How about a very large black and white photo of something that is YOU (motorcycle, closeup of a favorite musician, etc.)? And a coffee table as previously mentioned.

Do you have pics of the rest of the room?

Coffee table goes in front of the couch, it looks like there is room. Table should be close enough to lean forward to place your martini glass on the coffee table, but not so close it is difficult to sit. A modern looking coffee table like this one by Platner (actually designed in the 1960s) would complement the stainless steel legs in your couch and chaise. Or a side table of that design, located where the plant is in your photo at the top with the yellow pillows.

Then put an end table where you have the fiddle leaf in your mockup - with a lamp on top of it.

Hello Ronald R and Houzzers!

Looking good! Love the pillows and any color you like should work but consider the colors in rest of area espec if in same room. Please consider dual purpose items since space is limited. Consider C-tables or dual purpose nesting/ stacking stools as well as tree stumps. Easily paint if the colors aren't right but the price is. There are C-tables that can serve as a table but also be flipped to use as a seating bench. There are 'tree stumps' that can serve as a small table or a stool. See /query/stumps/nqrwns Sometimes they are dipped in black paint for a modern aesthetic. If you go for a dual purpose item, be sure to check weight limits. Check around for nesting stools in a modern aesthetic as well because your sectional being modern probably has a low enough seating height that the nesting stools can be dual purpose as tables and seating but store on top of each other. Carry them outside for parties, too, if you have a solid patio. The fig/plant adds to the space so if you add lighting, go for narrow or hanging where it will be of use to you. Make sure your light works for a live specimen. I like the rug idea to define the space. It is end of season for outdoor rugs. They can be easy to clean, look great inside and can come with little color. For Houzz query results, click this link modern rugs. Query their floor & hanging lamps as well. Minimalist in taste or not, you'll probably want rug, small table, and an additional level of light later but simply add one thing at a time as you live with the space and your wants make themselves known. For now you could get a tray with sides to set upon the sectional for drinks and remote. I suggest a silcone mat inside the tray if it doesn't have a non-slip type surface. Your throw blanket is great start as are the pillows with color. Congrats on a great start.

A coffee table typically goes in front of the seating area. There is plenty of space. Without it, you have no place to put a drink, book, snack.

Your couch leans more contemporary than modern IMO. If you are trying to achieve modern, I would avoid the pops of color and add natural textures. Wood, leather, metal. The tree is a great addition. I liked the recommendation to add an arc lamp. I like the last rug posted by Esmaili rugs. You could also do a cow hide. This one is nice. A little color but nothing overwhelming.

https://www.roveconcepts.com/sandro_bennett-coffee-table.html

https://www.roveconcepts.com/kure_lasse-coffee-table.html

https://www.roveconcepts.com/rove-classics_platform-bench.html

https://www.roveconcepts.com/sandro_sienna-coffee-table.html

If you don't feel like there is room for a coffee table, maybe an ottoman or a few small ones.

(not with the cow hide rug)