while those may seems like prevalent tropes I can number 1 assure you that this isn't true and number 2 let you know that there's a variety of ways to build or create chemistry between characters + their respective love interests, you've just got do do a little more than surface level reading into romance stories (or other genres with successful romantic subplots)
I'll note I'm not a person who writes or has big interest in romance but this is one place I've seen writing resources on building character relationships (be sure to rely on multiple sources though, lest you end up with a narrow perspective)
http://linkeepsitreal.tumblr.com/post/148353576279/tips-for-writing-romance-from-a-passionate
Personally I don't mind some tropes but I also seeing them subverted (of course when it's done well and not solely to jab fun or be snide). One easy way to see "ship dynamics" would be to look for them in exsiting media or just take a quick deep dive through good ol tv tropes.
Some of my own character ships or personal faves to read are usually built on character foils, how does one character compliment the other in terms of personality or behavior. Other things to look at is how the characters interact, what chemistry do they have, what's their relationship before becoming a cannon couple or someone is established as the love interest.
A big thing is interactions will play a key role. If the MC and their love interest have not once interacted or their interactions are barely meaningful then their relationship dynamic will fall flat.
There's probably other folks who could give better worded advice but I do hope you're able to find something that works 