Don't Make Drastic Changes
Don't try to wake up at 4:30 AM if you've been waking up at 9 AM previously. Such a drastic shift in your sleep schedule will surely come back to bite you.
First of all, such a drastic change will demoralize you in the morning, and you're likely to abandon the early morning routine altogether once again.
And if you manage to actually wake up that early off the bat, you'll probably revert to sleeping late shortly thereafter because you're so tired throughout the day, you can't take it anymore.
I've tried this strategy many times and I can assure you it doesn't work.
Instead, gradually wake up earlier every morning so you won't notice much of a difference from morning to morning.
For example, when I used to wake up at 9 AM, I'd set my alarm 15 minutes earlier every night until I was waking up at 6 AM feeling refreshed.
What's the bottom line here?
Instead of making a huge shift in your sleep schedule all at once, try making small changes every night until you reach your desired wake up time.
Respect Your Bedtime Routine
Training yourself to wake up early and staying up late past your bedtime don't go well together - something's got to give, and for most of you it will be waking up early.
Don't underestimate the power of a sound bedtime routine. Your bedroom should be your temple, not a place to stay up all night on your phone.
First of all, set a bedtime and stick to it. If you want to wake up at 6 AM, you should probably be in bed by 10 PM.
And that doesn't mean in bed on your phone. That means in bed, with the lights off, or at the very least, reading a book.
Aside from being addicting/making you stay up later, your phone's screen will keep you awake when you're trying to sleep and decrease your sleep quality.
Reading a book on the other hand doesn't emit any blue light and will make you tired quite quickly.
You don't want to associate your bed with anything else aside from sleep. If you consistently stay up late on your phone while in bed, you'll associate your bed with your phone, not with sleep.
Once I stopped using my phone or computer in bed and only reserved it for sleeping, I fell asleep MUCH faster once in bed.
While we're talking about going to bed earlier, exercise can help you fall asleep faster and will improve your quality of sleep as well. At the end of the day, you need enough sleep to feel good in the morning.
Drinking coffee isn't a replacement for a sufficient amount of quality sleep.
Go for a run, walk, bike ride, hit the gym, etc. and you'll have a better night's sleep, which makes training yourself to wake up early easier.
You can also habit stack - that means stacking one good habit after another. For example, you can wake up early to work out, and then you'll have an easier time waking up early the next morning to work out again.