I am PHP developer for around 3 years. It’s not long but enough to have some experience to share.
1. Read books, tutorials, videos, course, youtube
Even you don’t have enough time to finish all the books, however you should spend time to take a look at them everyday, little by little.
2. Participate in developer events in your town
Not only PHP, but all events related to development. Meetup with real people, learn to share and discuss with them, learn to socialize.
I learned a lot from these events. You don’t have to participate all the events, just do when you have time and want to relax.
3. Back to the basic
Spend less time for new framework, spend more time for data structure and algorithm, learn how to solve the problem.
SOLID, Computer Architecture…
4. Learn other language:
Ruby on Rails, Nodejs, GoLang… new languages appear everyday. You don’t have to be an expert, just learn and improve your skills, broaden your view about the technologies.
5. Learn other skills:
Cooking, music, photography, riding bicycle, playing sport… it’s good for relax.
6. Have pet projects:
Learn to code it in different way with what you often do to solidify your skills. Because it’s your pet project so you can implement in the way you want.
7. Travel and enjoy the nature:
Sound funny right?! Sometimes we should take a break and come back to the job, the problem with better view/mind.
And many many other way to get your skills to be improved.