1) If you're male or masculine-presenting, you'll probably have more trouble. The gender breakdowns on these apps are pretty brutal, and a lot of women on there are swiping for validation.
2) This is easy-beanz advice, but have good pictures. Try to avoid too many selfies, and see if you can have friends/family take nice photos of you outdoors or doing fun activities. If you're taking pictures inside, try to avoid taking them at night and instead capitalize on natural light as much as possible. The most important thing you can do is have good lighting, or a really good reason to justify the bad lighting (i.e a moment that you could literally never capture again and is amazing)
3) If you have a dog or another cute critter, FEATURE THEM! Honestly even if it's a friend's dog. It's ok to put a disclaimer that its not yours, some people just like to know that ur cool with animals :)
4) Try to incorporate conversation starters in your photos. Like you playing your favourite board game, or a funny picture from a memorable night. If the picture is super ridiculous try and put it behind your super hot pictures.
5) Try to make your bio authentic to yourself, while still remaining mostly positive, OR playfully negative (where you're obviously joking). Theres nothing ~technically~ wrong with sharing things that you're annoyed at or upset by, but if it's one of the first things people see about you, they might assume that you're a weirdly picky/closed off or jaded person.
6) Bio Length [this is my subjective opinion but]: Keep it snippy if it's a mobile app. Have the relevant information there (what you're interested in, what you want out of being on the dating site, a strong (but silly) conversation-starting opinion that you hold). I personally get a bit scared off when people write their whole life stories on there, just because it signals to me that someone has a lot of investment into this whole thing, and that puts a lot of pressure on me, the person matching. That being said, some people are looking for that investment. I just don't know if it's the majority.