In a map, have you seen HL i think it was hl? maybe tfc? well on this map all the people are slashing at gates to vote for maps, lots, lots, and lots of metal doors, and they are really strong, all you have to do is hit them with a crowbar millions of times and they break? thats a good way of voting. instead of nominating and voting with amx, just make a map thats a big building, with lots of doors. Make the doors breakable, make them really strong. Make them big too. Basically the point is, the more people breaking at a door the faster it breaks, and thats that, each door broken leads to a different map. How? Its a changelevel entity. That entity is in a halflife fgd only. Its so you can vote. Best to make your own though, other wise you will get errors if you dont have certain maps and the server will shut down, so make your own with your own maps.
You will recognise the entity as soon as you see it. Its a tie-to-entity one. All you do is choose what map to change to and YAYYAYAYAYAYYAYAYAYAYAYAYAAYYAYAYAYAYAYAYAAAAAA you got it!
you wont get popularity for this though. people prefer voting to this, because this method takes AGES, due to taking ages to break the doors and voting is much quicker.