1 . pick one hero from each Agi , Str , and Int , pick the agi carries ..
and the str must be a war initiator and a tanker ( ex : levi , centa , tiny , magnus , etc .. well , i recommend levi because it can be a good tanker and his ulti is a widest AoE spell in dota ), the Int must be a support nuker , ( ex : zeus , lich , akasha , etc , i recommend lich because the cf is really good for semi-war initiator )
2 . pick based on hero roles , note that a support wont always be int , an str/agi can be a support too
- carry , semi-carry ( well , it must be a ganker , ex : viper , venom ) , support ( i use this a lot when i dont have enough player to play 5v5
- carry , carry , support ( this is a risky play , but if u are good enough , u can pawned ur enemies in late game )
- and there is still so many of them
3 . pick on combo , always remember to balance the team , dont pick all str just because it has a good combo . ex : nevermore , magnus , darkseer .
hope this helped u
, i'm still a newbie on this game, but i will do my best ^_^
Note : sorry for bad english