Greeting Adventurer!
What cloud havo says is true, but you can also may an alt character and do main quest again it can give you lot of contri pts exp, try finishing chapter 4 then delete your alt and create again. If this is so hard for you, you can also try repeatable quest, go to Balenos on the map, then go to Altar of Agris then do the repeatable quest of killing steel imps, you need to kill 20 steel imps and it will reward you 50 contri points, you can finish this quest in less than 2 mins rinse and repeat it can give 2-3k contribution experience in 1hr. or you can do high level repeatable quest that suits you to rack more contribution experience rewards. Good hunting!
thanks for the tip with amity quests, i didnt try it, what i did is level a 2nd char to 55 and did all the main quests, gave me around 30-40 extra contribution points, but now my town hall is lv5 and i have still not enough contribution to employ all workers and they are all green/blue quality, cant afford the good ones...sucks imo...would apreciate if they would increase the daily quest contribution by at least 1000%