I have no clue what a Dopp kit is either but I think a tote bag is perfect for a man. I probably wouldn't embroider his name on it though.
Best wishes for your sister.

A dope kit is a small bag for putting your tooth brush, make-up, comb, etc...
I grew up calling it toilet kit.
"A rose by any other name would smell as sweet." Shakespear.
Mike

Now that we know a Dopp Kit is a Toiletry Bag/Kit ....... I'd vote for that for both the men and women.

It might be a welcome change to "another" Tote Bag.
Many people have so many of them already, and this might be a more original gift.
And to say the least, quite usable too!

I would do a tote for a man or woman. Men go to the beach and buy groceries, and have books and umbrellas and things to carry.

The toiletry kit seems nice for men/women, too, but since you've already made the tote bags and embroidered their names on them, I doubt you're going to want to switch course at this point.

All the ideas are good, but I find tote bags are great. My football team tote holds library books. My cat tote goes to guild meetings. And so on...each tote is for a different activity. They stay packed with items necessary for that activity and I can just grab and go. Saves time and brain power!

Put a flap on it and make it a messenger bag. Make it the size of a tablet, then he has the options of his tablet or his phone and wallet. Or, add some PUL fabric and make it a lunch bag.

I had to google the source of "Dopp", which I heard years ago, but the questions made me curious. According to Wikipedia: "Dopp kit is a term particularly in use in America for toiletry bags. The name derives from the early 20th century leather craftsman Charles Doppelt, whose company designed the case in 1926." So now we know.

I made one for my young grandson one time, and can tell you they're as easy to make as any bag.

I'd go for the tote bags that can be used for grocery bags, I HATE to pay for plastic bags when visiting relatives in states that don't have bags anymore. They can be used for anything.

Look for blue ribbon fabric for prostate cancer awareness? Do they make it? That would be gtreat for a guy, or make a tote with a blue ribbon applique?

We always called them Dopp kits in the military, as did our Dads generation too, and now our sons.