After having more or less spun plates for the last 18 months, I've come to the conclusion that a healthy LTR situation is more conducive to the stable happiness of a man than having multiple sex partners or engaging in regular one night stands.
That said, it is better to spin plates than to be involuntarily celibate.
Involuntary celibacy < bad LTR < one night stands < spinning plates < good LTR
The reason why long term relationships are preferable to spinning plates and one night stands is based on the price and quality of sex in them. With a one night stand, the quality of sex can't be guaranteed, while the price can often be high: My average one night stand consisted of a tinder match, some witty banter, some more banter over text, maybe a phone call, meeting them in person in public, circling back to my house, often dealing with some LMR and ASD, and finally getting to it. Sometimes I got very lucky and there was a low investment night with a hot girl, but these happen months apart.
The quality of the sex, too, was nothing in a ONS compared to the quality of the sex I have with my girlfriend because of the lack of sexual familiarity that you have in a long term relationship.
The investment required to get sex in a good relationship is laughably lower than it is via a one night stand or even a plate: “Still on for tonight at 7?” Done.
There are a handful of rules that are important to follow to cultivate a healthy long term relationship. These are not meant as absolutes but as general guidelines which mitigate the major pitfalls in relationships.
Do not cohabitate. (I will assume I don't have to tell you to not marry) There isn't any way that cohabitating with a woman will increase the attraction between you two. It will make it much more difficult for you to use constant dread game to keep your woman in line, and will altogether erode the psychological autonomy you have when you have your own space and time away from your girl.
Spend money on her proportional to the value she adds to your life. Does she bend over backwards to make you happy? Take her out to dinner. Does she scramble at the opportunity to fix your clothes or rub your back? Buy her a flower. Never invest in her financially prior to her providing value. Under $5 doesn't count, i.e., ice cream / coffee.
Do not ask for or promise sexual exclusivity. You are always free to bang other girls (ideally you won't want to, though) and she is technically free to bang other guys (ideally she wont want to). If your relationship is strong, you will tell her “I am not seeing other girls right now.” If she eventually demands exclusivity or else she'll leave, that's when you make a calculated decision whether to bail or to commit. The primary reason for not committing is the constant dread game that it integrates into the relationship. When she knows at any moment you could be out banging another girl, without guilt, it prompts her to 1. Be very sexually generous with you while you're together, 2. Be on her best behavior so as to keep you emotionally invested and less likely to sleep with someone else.
Never give her negativity or toxicity. If you always treat her with respect (teasing and farting on her is not disrespect), you will always have the upper hand in any future disagreements. If she becomes toxic, she will realize she started it and should eventually recognize that and apologize. Never giving a girl negativity avoids a massive world of drama that negative people have to live in. If you are always positive, and she is still negative towards you, without apologizing afterwards and making amends, go no-contact or simply say “Don't contact me again, we're done.”
Do not see her every day. My personal preference is to see the girl I am dating twice a week. Each time, she stays the night at my place and we spend approximately 12 to 18 hours together. Seeing a girlfriend every single day is an attraction killer and shouldn't be done really at any point of the relationship. You need time to miss her, and you need her to miss you. This is why I don't travel with girls. Day 3 and I will already hate them.
Text game is strictly logistics and jokes. Never discuss emotions or the nature of the relationship over text. Ideally, avoid discussing the nature of the relationship at any time. Occasionally it must be done, but this should occur very rarely. You should be banging her 75 times for every time there is a conversation about “where we stand” or “where things are going.”
Feedback is appreciated as these are not convictions but hunches.
LT;DR: A good relationship is the system of female interaction which is most conducive to your well-being as a redpilled man. This is based on the quality and price of sex in a relationship versus ONS and plates.