how do you maximise the points you gain from winning

The way the game ends (checkmate, stalemate, resignation, time forfeit, etc) doesn't affect the rating change.

The amount of pieces captured also makes no difference.

The rating formula takes into consideration 4 numbers:

1) your rating

2) your opponent's rating

3) A universal multiplier that the website or organization can adjust to increase or decrease gains and losses (for example you wouldn't want people to lose and gain less than 1 point, or as many as 100 per game).

4) A multiplier for each individual that the formula self adjusts based on the reliability of a player's rating. This is known as your RD. Reliability basically means how frequently you play. For example new players really will gain or lose 100s of points for a win or loss, but only because they're new. The more they play the more this multiplier shrinks until a player gains roughly 10 points for a win vs an equally rated opponent. If you stop playing for a whole year, for example, this multiplier would again be really high for you.

A quick and easy way to know what the approximate adjustment will be is with this kind of table.

Basically you take the percentage as a decimal (in the H or L column) and multiply by 20, and that's how much your rating is adjusted. The number 20 is roughly the universal multiplier I mention in the first post.

Rating diff is difference between the two player's ratings.
H is % of points the higher rated player is expected to win in a match (wins are 1 and draws are 0.5 notice if only 1 game is played, and you win it, you've won 100% of the possible points)
L is % of points the lower rated player is expected to win in that same match.

So for example lets say you beat someone rated 200 points higher than you. As the lower rated player you were expected to get 24% and you actually got 100%. The difference is 76% so you'll earn .76*20= ~15.2 rating points if your RD is low. 

Lets say you draw someone rated 150 points lower than you. As the higher rated player you're expected to get 70% and you actually got 50%. The difference is -20% so your rating is adjusted -0.20*20= -4 points if your RD is low.

poodle_noodle do you know if that's calculated before the match begins (like in "live" games), or when the match ends?

Diamond members have a 2x rating point multiplier

Poodle Noodle has not been online for 2 years

I won a match and I earn zero point!

My rating is 1618 and opponent's rating was 385.

It was a team match.

But zero point, really?

Correct. If you vastly outrate your opponent you don't get any points for winning.

@Martin_Sthal, in a team match you don't have choice to choose opponent. So I was paired with this very low rated player. It should be a principle that a win should earn at least one point and a loss should deduct at least one point. There is some respect in winning.

why am i only getting one point per victory but potentially losing hundreds

You only got one point on your last win due to the rating difference between you and your opponent. Had you lost that game, you probably would have lost a lot.

Your other games are more than 1

every time i must play against 1300 and so but i barely get any points

How to score Bonus point in the League?

That's not what this topic is about but play Arenas.

Archeological maths...

It's not true. Not sure you can call it a myth though

Fun bit of trivia... if you play the same player two games in a row, if you lose the first game and win the second you'll have a higher rating than if you had won the first game and lost the second.

The difference is a fraction of 1 rating point... but still