they were an individual that I needed to treat individually based on
I needed to treat individually based on their personality, skillset, communication style, motivations,
desires, dislikes, etc. But I consciously avoided differential
treatment of women (and...) - in part because it could be viewed as
discriminatory in my locale, but mostly because I thought that was the
best way to build a team
Of course this is necessary. If you have no particular culturally-induced or personal bias against women (etc...), and neither do your colleagues, then this would also be sufficient and therefore would form a sensible complete policy. Some would question whether it's possible or probable to grow up in our culture and be free of such bias, and you can agree or disagree with that as you see fit. All I can say is what to do if you suspect there might be bias and you want to reduce it.
So, if you don't examine your treatment of different personalities, different skillsets, different styles, and all the rest of it, with a view to whether or not you are exhibiting direct or indirect bias against women (etc.), then you're falling short of the highest standard. If you're a large enough institution, you may even be falling short of the bare minimum acceptable standard in law or basic decency.
Examples of indirect bias abound. In some cases they are created intentionally with the purpose of disadvantaging the target group. Don't bother trying to defend the "separate but equal" doctrine, or pre-civil-rights voter literacy laws, with hindsight. But for a while they held up as ostensibly non-racist.
In some cases they're accidental but prejudicial, for example you might unintentionally judge someone's "enthusiasm for the job" in part by their willingness to do overtime at short notice, ignoring the fact that childcare responsibilities are, for reasons that have nothing to do with people's enthusiasm about their jobs, not equally balanced between the genders in your society. Then you would be ascribing as free choice something that, to someone in this hypothetical society, is in fact somewhat constrained by their gender role. Of course in theory one would only use willingness to do overtime to judge someone's availability for overtime, not their enthusiasm for the job, but it's very easy to ignore what contributes to your "overall impression" of someone.
In some cases indirect biases might be trivial, and raising them is a fuss about nothing. For example, it turned out on balance that requiring women to wear shorts/leggings to play football (by which I mean soccer) was way more sensible than making any kind of special accommodation to invent a version of football that could be played in whalebone skirts and corsets. That is a joke, the serious version of the issue is what happens in countries where women are constrained by law or public sense of decency not to dress as is best to play football. Then, through no choice of their own, they require special accommodation in terms of playing attire if they're to play at all. If you cannot eliminate some prevailing sexism, then it is not "sexist" to try to mitigate it, even if the result is different treatment. If the prevailing sexism were eliminated, then naturally the different treatment could be brought to an end.
To make women feel welcome (or members of any group rare in your workplace that you're concerned may suffer from exclusion), you need to not just apply your standards of judgement while ignoring the possibility that prejudice or bias might occur, you need to actively check whether any is happening in the workplace, because not all "equal treatment" is the same in this respect. Expecting people to wear red is gender-neutral, expecting people to wear a beard is not, even though "some men can't grow beards", "women could get fake beards", "I'm treating everyone exactly the same, the only difference is some people can meet the standard and others can't", or any other objection someone might raise to political correctness gone mad when this beard policy is questioned. Expecting people to wear pink, even, might not be gender-neutral, depending how people typically respond to pink clothes in your locality. That in turn is cultural. The general public's responses are unaffected by your careful treatment of people as individuals: you can set a good example but you can't affect everyone.
If you can examine yourself (which nobody can perfectly), then you don't "treat people differently because they're a woman", but you also avoid unintentionally "treating them like a man even though they're a woman". I have intentionally used extreme examples throughout, so as not to delay on explaining just how the reasoning follows. Your task, should you choose to accept it, is to identify any less clear-cut cases that really do happen in your workplace and that might contribute to an unwelcoming atmosphere, or even to an impossible environment, for most or all members of some particular group.