* Salary compression is real: most companies are not going to keep giving you raises to match what the market would give you for your skills. They would rather you leave and take all of the institutional knowledge with you than pay you the amount you could get elsewhere. Even if that means hiring someone else at market value.
* Don't get comfortable at a company to the point you're not getting new experiences and learning new skills. Don't become a dinosaur.
* Even if you don't want to become a manager, when the time is right and you have the right skill set, demand a title with "architect" or equivalent in it. Titles are B.S. but people listen to developers with "architect" as part of their title. I insisted on the title and now I'm being recruited for much higher salaries even though I had the same responsibilities as a "senior".
* Good local recruiters are your friends. They can tell you salary ranges for a job and they do a lot of the hard work for you.
* know how to calculate your contract rate if you're doing contract work. Your rate will be different if you are a W2 contractor vs a 1099 contractor. Take into account self employment taxes (1099), the lack of PTO, the time between contracts etc.
* Whether you are a contract or perm, realize that you are still your own company. Your employer is your customer. Do you your best work but never feel a sense of loyalty that keeps you from jumping ship for higher pay. They don't have any loyalty to you.