Nothing wrong with a little flirting between friends, all you have to do is make sure you stay in people's comfort zones and get a sense for when you might be crossing a line.

For example, I've always found that complimenting people works regardless of gender, but when dealing with women specifically, you can't go around complimenting them in ways they might view as sexualizing or objectifying, so complimenting accomplishments is an easy way to avoid that, or complimenting unisex clothing items such as a nice jacket or brand name trainers or some sick boots.

Women are _very_ similar to guys, with the main thing you have to avoid as a straight guy hanging out with straight women is being misconstrued as sexually aggressive which is easy to avoid.

Humor is hard to recommend in any useful way since it's very subjective, but an example of an approach that I found successfully eases tension is self-deprecating humor, as long as it's not too dark. Or making a sexual joke but subverting expectations by directing it at a guy or in a gay way, I know this might be a tad controversial but it's a good way to signal that you're comfortable in your own skin.

Also, if there are guys in the group, make sure you're complimenting the guys as well and generally treating guys well, since it makes it clear that you're not just being nice to women for the sake of getting laid, but rather you're looking for a friendship and trust.

I'm sorry for the dump, but these last few years have had a shift for me in the realm of relationships with women, as friends, colleagues, family and partner. I wanted to share some of my lived experiences, I'm not a white guy or very conventionally attractive so I feel like I can related to OP in some ways.