In order to master handstands and hand balance in general you need to eventually practice everyday, sorry no quick wins or fast hacks to master handstands, however it's not just about hard work, because working hard is important but working smart is just as important.
When practicing hand balance we place our body in un-familiar and un-comfortable positions. These positions are putting your body in a state of potential injury if not noticing Technic and physical limitations.
Do not overload your wrists and shoulder blades
A rigorous daily repetitive practice of inverted positions "taxes" your wrists and shoulder blades and exposes the body to injurious and inflammatory reactions. The good news is that our tissues and joints in the shoulders and wrists are getting stronger and more durable also if we put gradual stress to progress. So make sure that when you get to a daily practice only when your joints (mostly wrists and shoulders) are "ready" to take the load.
Repeat and diversify
We've all heard the phrase "repetition is the mother of all skill", and it does have a lot of truth, however also diversifying your practice can help. A rule of thumb would be: keep repeating the basics like chest to wall, improving the line, opening shoulders, slowing down the breath etc. and also try to explore new territories every once in a while so like that you might find out other new hills to concur.
Technic Vs Strength
Maximum efficiency comes with maximum Technic, strength compensates the lack of Technic until you develop it. So high level hand balancers are not relaying on strength but on efficiency by Technic.
Slow and incremental improvement
Patience is a key component in mastering handstands, it's a slow and painful process for most of us, no one is expected to immediately jump into a free handstand, you should start with basics such as downward facing dog position and handstand with a wall for a longer periods of time. When the shoulder flexibility is limited or the hips flexors are tight and the range of motion for a straight line from the toes to the finger tips is not perfect you should work on improving the range of motion instead of jumping to a more advanced steps such as pressing to handstand or a one arm handstand.
A clip from Athleticult's handstand class, here we work on basics and the ability to fall correctly, so you can practice handstand in the middle of the room with no fear or risk of falling