So much has changed since RBY. Back then, I had no idea about how to build a team, I used moves like Cut and Strength on my Charizard and didn't know Dragonite had weaknesses xD
In GSC, I learned more about types, I started to learn about stats and also tried to have different types on my team.
In RSE, I finally started being a Pokémon trainer. I started to include strategies on my teams, I learned more about Physical/Special moves, weather, and improved my skills and knowledge a lot. That was also when I started looking at serebii. Colosseum gave me a lot of knowledge about Doubles.
The 4th gen brought my entrance in competitive play and I learned how to breed and EV train properly. I could build a successful team for WiFi Doubles. Ingame, the game just became easier and easier as my prediction and team building skills improved.
With 5th gen, I tried to continue the same path that I had chosen in 4th gen. Same play style, new team, new options. But right now I feel like my playing style and my "standard" team concept are well established and I only need to try more options and practice to lead my Pokémon to victory ^^