How do you win contests in Pokemon Diamond?

Answer 1

there are many ways to do better in contests.

1. give your Pokemon a lot of poffins! it can help a whole lot.

2. enter a contest that is compatible with the moves your Pokemon knows. look at your Pokemon's summary and see if your Pokemon has smart moves cute moves or whatever.

3. in the 3rd round use the moves that can get you extra points.

That's all I can do for you. Just try your best and I hope you win!