What's your angle? There are men here who would fit this description and a couple of women (myself included) that may be able to offer some insight. Perhaps
@Asmodeus or
@Ronaldo7 can elaborate.
Certainly some might say don't approach at all & let the women come to you (but this will depend on your particular draw.)
I'm myself seeing a man who could be described as emotionally unavailable. Been seeing him for about 15 months or so. I was looking for a plutonic social dancing partner online and we met that way (he approached me initially online as someone who also enjoys dancing.) He noted in the initial exchange that plutonic "works for him" since he misses female companionship but isn't looking for a relationship. Very transparent right off the bat.
There needs to be attraction to one degree or another to dance well with someone, so we met up to chat. When he walked in the plutonic thing went out the window (for both of us). We ended up going to a dance venue and chatting instead of dancing. Ended up being the best first date of my life. In fact we have yet to go dancing at all. It's rather ironic.
I don't think you would approach any differently than you normally would.
What you do however, it is set firm boundaries about the expectations in the interaction. It also depends on what the woman is looking for. If she wants a LTR or marriage things will get rocky fast. In my case I have children, an ex, several businesses, and a busy life. I also live far away from the man I see. This works well for me since I don't necessarily want marriage again.
He makes time for me when I am in his area (even if it means a couple of hours drive for him each way), and there are no entanglements for me where I live, and no entanglements for him where he lives, has family & does business. Who either of us sees or what we do outside our interactions are none of the other person's business.
Neither of us has ever asked in any way about what the other person is doing when we are not together, although we both tend to reassure the other about things (example, this past Sat. his phone pinged at 3am on the bedside table. I heard it but said nothing. Obviously it could be someone else that he sees or his ex-wife who he may still have some involvement with - none of my affair...but in the morning he made a point to tell me it was his 18 year old son getting home late & letting him know. True? It doesn't matter. My point is he made an effort at least to allay any insecurities I may have had, but without me asking for that reassurance.) True or not this is a kind gesture...and I of course would never look at his phone, I take him at face value.
Now this arrangement would not work so well if I was insecure in any way. He is a high SMV man with options. I have options too. I personally think each of us appreciates that we are an unusually good match and we enjoy one another a great deal when we are together; we are an attractive couple when we are out socially, and we just fit. But neither is pushing the other for anything since life has its constraints and neither of us is going to uproot children & move cross country. We don't have touchy feely conversations. We don't fight or argue (although we disagree about some things.)
I have told him I love him (I do) but I love him from a standpoint that I give freely and without expectation. He is free to go at any time. He does not tell me how he feels but his actions show me that he likes me and cares for me. He is warm and protective, he treats me with kindness and respect (I finally was able to talk him into me buying him dinner the other night, I asked permission, he acquiesced - he typically insists on paying.)
He will share emotionally now at times but we are more than a year in and have become friends at the very least. I introduce him as a friend to others. I assume that he is not interested in a "relationship" (even though we are sort of in one anyway) unless he tells me differently. He is not the sort of man to pressure. He also is recently divorced from a very wealthy BPD woman who is the mother of his children so he has ridden the crazy train and she still tries to exert control over aspects of his affairs.
He has commented about how nice it is to spend time with an accomplished, sexy, stable woman without the drama...but it is not lost on me at all that some men crave drama and he may not have that need met with me. He has narcissistic tendencies to be sure, but things are in a nice place.
He remains emotionally aloof, very private. I tend to be more emotionally aloof than many women and as I noted this works well for the two of us, but its not for everyone.
Where women run into problems is in thinking they are going to "fix" or "rescue" or change a man who is emotionally unavailable. It is always better to be cool with the way things are rather than setting about making things meet some set of expectations or fantasy land that someone sets up in their mind. I've seen men do it too. Then the fantasy gets dashed on the rocks of reality. Much better to start off in reality, enjoy the ride, but stay rooted in reality rather than fantasy land.
This requires a pragmatic approach, something only an emotionally mature and/or detached person can muster.