The arithmetic
How to improve your gambling skills
Three skills transfer across every game: picking the cheapest version, executing correct play without thinking, and holding stake discipline when you are losing.
Everything else that gets called a skill is either superstition or a narrow edge in one specific game.
Practising correct play
Free tables exist for exactly this. Deal two hundred blackjack hands against a chart on a demo table, checking every decision, and stop when you no longer need to check.
That is a real skill with a measurable value, roughly two percent of everything you stake at that game, and it takes about an hour to acquire.
Practising stake discipline
This one cannot be practised on a demo, because a demo balance is not money and your hands know it. It has to be practised with real stakes small enough that discipline is easy, then held as the stakes grow.
The test is simple: does your stake ever change because of the previous result? If yes, the skill is not there yet, regardless of how well you play the hands.
Where real edges exist
Poker, because you play other people. Sports betting, if you specialise narrowly and shop prices relentlessly. Video poker on a rare full-pay paytable.
That is the list. In every house-banked game the edge is fixed by the rules and no amount of study moves it, which is worth accepting early rather than after two years.