TL:DR Approach everyone without judgment, use demographics and your interests to best pick where to meet people, be a regular, don't use alcohol as a social crutch, and act on impulse.
Asktrp is frequently filled with questions about meeting people and approaching, but there is never much comprehensive said on the subject. Most of the time people just say "Approach five women a day!". While good advice, there is more to consider to increase your success in building a social circle and meeting women.
Meeting People 101 is a compilation of advice I've given and received on the matter. It is not exhaustive or all inclusive, but should offer a great starting point for many.
Approach Everyone, Not Just Women. And more specifically, not just women you find attractive. Focus on meeting people. Lady spilling her life story on the subway? Engage her. Young skater kid at the pub? Engage him. Seemingly crazy homeless guy outside your favorite watering hole? Engage him.
Rid yourself of judgment and engage with everyone. When learning to connect with people it's helpful to talk with people different than yourself. Stop trying to weigh who people are through appearance and start learning people first hand. The more varying the people you talk with the wider range of people you will be able to connect with.
You may be asking what this has to do with sexual strategy. It's simple: social proof. The ability to connect with even those very different from yourself shows value and leadership. Social acumen is an indispensable trait.
Know Your Demographic. Know what type of people you are looking for and figure out where to go that best fills that demographic. Dont go to clubs and bars every weekend then wonder why you can't find a girl who isn't promiscuous, or go meet people at the mall and wonder why everyone seems so vapid. I've found the best way to find the demographic you're looking for is to...
Make Use of Your Hobbies and Interests. Find social situations centered around your favorite activities. For example, I juggle, slackline, and do other object manipulation type of activities. I found a group that meets almost everyday at my local uni that does these things, and I post up there meeting like minded people. Strangers consistently come up out of interest in my juggling, and wouldn't you know it, some are attractive women. From there its only a matter of time before I'm teaching a cute thing how to properly toss my balls.
Other examples would be reading groups if you're a reader, or open mic nights at coffee shops of you like poetry, or the climbing gym if you like climbing. If you don't have hobbies, get some you boring schmuck.
Use Convenient Locations. I often talk to women at a local book store. Not only am I a fiction lover (hobbies and interests), the bookstore has a coffee shop, which can make a date-close immediate and easy. Find social locations near date locations.
Be A Regular. Some of the best social proof you can have on a date is to go somewhere where people welcome you as a friend. Make connections with your bartenders and waiters. Get on a friendly first name basis with as many people as possible, in as many places as possible. Appearing to seemingly know everyone is quite becoming.
Don't Crutch With Alcohol. Everyone can get drunk to lubricate their social skills, but no one gets drunk and actually improves them. Relying on alcohol in social situations can actually lead to social anxiety when you are not inebriated. Learn to connect without the aid of the bottle.
Engage Impulsively. This is non-negotiable. If you don't learn to start conversation with strangers on that initial impulse, you will always be stuck behind a wall of hesitation. Make eye contact with someone? Just fucking say hello. If you do not give yourself time to think about it, there's no way you can build that over-investment and wuss out.
Lessons Learned: Developing a social circle and meeting women isn't rocket science. Place yourself in locations and situations that align with your personality and the type of people you're looking for, and make connections with as many people as possible.