How do I make a masculine Valentine's Day gift?

I would start with hobbies and maybe make a basket with things that he likes but tie with red curling ribbon.

There's always coffee mug if not over done.

Personalize underwear.

Heart shaped cupcakes or brownies or just trimmed with red piping.

Bake bread or make candy and wrap in red cellophane or tie with red ribbons.

Print off some valentine labels and put on his favorite beer or soda.

A clear jar filled with his favorite snack with a valentine's gift tag.

One lady I know has a hubby that likes beer so she bough him beer. But each bottle was an unusual brand and flavor. There were flavors and types he wouldn't normally have. He loved this.

You could always give him some red boxers. Or take a pair of white boxers and add red decorations (hearts, lips, cupids, to personalize them).

Make him a heart shaped air freshener for his vehicle.

If he smokes cigars cover a cigar box with red tissue paper and fill with his favorite cigars.

Make a romantic dinner consisting of his favorite foods. Put a red table cloth down and put little cupid pr heart cutouts scattered about.

Make him some chocolate covered bacon. Believe it or not this is a very popular snack. Shape the bacon into heart shapes before cooking for an extra Valentines Day slant.

Make him some bourbon scented candles.

Adorn stuffed pillow with red felt lettering. You can make an I love you or let's snuggle message on the pillow.

Put a big red ribbon on yourself

https://pinkfortitude.com/homemade-bar-soap/

I got a box from the flower store that would hold long stem roses. I made chocolate chip cookies and stuck artificial rose stems in each cookie, placed them in the box on tissue paper and tied it /w a big red bow. It really was a big hit.