I'm late to the party but I thought I'd add in my two cents.
Be yourself. For some reason, socially inept misogynist (aka, redpillers) think this means literally make never make any effort in being attractive. Be yourself means don't pretend to have certain interests/personality just to impress or attract others because then you're going to have to keep up with that lie and you'll end up bitter and resentful if you actually don't enjoy it. This is assuming you don't get caught in the lie first.
Be attractive. This means both physically and personality wise. Look at yourself in the mirror. Would you want to date/fuck you? Sure, you can probably find someone who likes you just the way you are but if you're looking to increase your odds of success, take care of yourself and be fucking hygienic. Shower, wear deodorant, take care of your skin and teeth, and wear clothes that fit. Those are essentials. That girl or guy you like does all that stuff so you shouldn't expect them to overlook the fact that you won't even make the slightest attempt at being presentable. Relationships usually involve some sort of physical contact and no one wants to hug and kiss and be around a sloth when they themselves take care of their appearance.
2b. Ask yourself what do you have to offer in a relationship. If one of those things you list is "being nice", you lose. Being nice is not some unique, hard to find quality in a partner, it's just a basic quality of every decent human being. So what do you offer? Are you fun or adventurous? Do you like trying new things? Are you passionate about anything? Do you have any hobbies? Do you interact well with others? What would you do if you did manage to go on dates with someone you liked? What would you do in a relationship? And no, showering your SO with love is not an activity. You have to actually offer something if you want to get and keep the attention of someone, just like you'd like them to be interesting and not just a pretty face to look at.
Stop expecting your life interactions to be just like in a movie/ tv show. They're scripted. They're not real. They're fantasy/entertainment. Relationships and attraction do not mimic the things you see on television and you really should stop expecting it to.
Don't put the person on a pedestal and don't turn into a doormat. The person you like is not some infallible angel so stop treating them like they are. Everyone is human and everyone has their flaws. A healthy relationship should not consist of you worshiping your spouse. You can accept and love someone despite their flaws but do not pretend they don't have any because once they show you their humanity you're going to end up feeling cheated when you shouldn't. Don't let them walk all over you either. Don't agree or concede to things you don't like just to please them. Not having a backbone is not asked of you so don't pretend you're some martyr who must sacrifice everything for their happiness.
Do not sit around stewing in bitter resentfulness if you're rejected. Rejection sucks but it's part of life. You can't force someone to like you and even if you could, why would you want to? Do you really want to be in a relationship with someone who you had to beg and pester to give you a chance? And even if you are desperate enough to emphatically answer yes, how long do you think it'd last and do you really think it'd be a pleasant experience to be with someone whom you have to convince or coerce into doing things with you?
There's probably more but I'm tired. Most of what's written above is a good start to getting out of the nice guy/girl tm mindset.