Wedding boutonnières for me and my partner - identical or just coordinating?

I made the flowers for my own wedding last spring and I'd say go subtle rather than matchy. My husband wore cream roses and I wore the same cream roses with a single dusty blue sprig tucked in, since his suit was dusty blue. Nobody at the reception coud tell they were 'matching' til you looked closely, and that little hidden detail felt more special than identical ones woud have. With navy and grey suits you could do the same wildflower cluster for both of you but give yours one extra accent bloom, maybe a soft sage or dusty pink thread you alredy have in stash. One practical thing I learned the hard way: crochet boutonnieres weigh more than fresh ones, so the pin tends to drag the lapel down. I glued a small piece of felt to the back of ours and ran the pin through that, and it sat flat all day. Also wrap the twine a bit higher up the stem than you think you need, then trim the ends short, because long twine tails caught on my husband's jacket pocket every time he put his hands in it.

If you want a keepsake version too, make a second set slightly larger and save them in a box with the invitation. Mine still smell faintly of the venue and it's my favorite thing from the day.

I'd push back gently on the subtle route and say make the matching obvious and own it. For my sister's wedding I crocheted both her bouquet accents and the groomsmen's buttonholes with the same drop of paint-coloured thread worked around the edges, and the photos look so much better for it. When everyone's piece clearly belongs to the same set, the whole wedding party reads as one picture. For you two specifically, I'd use the exact same yarn and the same little wildflower mix for both boutonnieres, and let the stems do the differentiating. His on a longer wrapped stem pinned lower on the lapel, yours shorter and higher, since a grey jacket and a navy jacket sit differently anyway. Twine tie-off on both keeps them looking like a pair. One practical thing from making about a dozen of these: crochet flowers weigh more than fresh ones, so test the pin on an actual lapel fabric before committing. A heavy little cluster can pull the wool out of shape by the end of the night. I ended up stitching a tiny felt backing disc behind mine to spread the weight and it made all the difference.

Also make at least three extras. One will get crushed in a pocket, one will vanish during photos, and you'll want a spare for the keepsake box.

Been crocheting little corsages since the 80s when everybody wanted them for prom orders, and one old trick that still works is stiffening the blossoms before assembly. My mother did it with sugar water, I use a light spray starch, either way the petals hold thier shape instead of going limp by the reception. Wire the stems too, wrapped in the thread itself, then hide the wire under your twine wrap. Holds up better than yarn alone if anyone gets hugged hard. One thing I'd check is how the navy reads under autumn evening light, sometimes it swallows dark colours entirely, so test your flowers against the actual suit fabric before you commit to a palette.

Start earlier than you think you need to. I did the buttonholes for my cousin's wedding two summers back and each little cluster took me around 40 minutes once you count assembly and wrapping, not just the flowers themselves. Multiply that by enought spares for the ones that come out wonky and it adds up fast. Also worth making one up in your exact planned thread weight before you commit, since a 4ply blossom sits very differently on a lapel than a DK one.

I'm with the subtle matching camp too. For my best friend's wedding I made both boutonnieres from the same little daisy pattern but gave hers one tiny burgundy bloom tucked at the back where only she'd really see it. The photographer actually spotted it during the couple shots and made a whole thing of it, got a close-up of the two side by side. Ended up being one of my favourite photos from the day. So an extra accent bloom on just yours sounds like the right call. Did you have a colour in mind for the accent yet, or are you pulling from whatever's already in stash?