How to get certain Digimon

Agumon : Take good care of your Koromon until he changes.
Betamon : Take bad care of your Koromon and leave him on one heart for both hunger and strength until he changes.
Airdramon : This is how I do to get him : Get a Betamon. Leave three hearts for both hunger and strength, wake him up twice at night and once after 8:00 a.m., do this until he's 4. Once he's 4, wake him up after 8:00 a.m. and set to his bedtime again and wake him up, do this 5-7 times. He will become an Airdramon when he's 4.5 years old.
Greymon : Get an Agumon and take good care of him.
Darkmon : You can get Agumon or Betamon to get a Darkmon, but the easier way is to get a Betamon and take good care until he changes.
Meramon : Get an Agumon or a Betamon. Take bad care and maintain two hearts for both hunger and strength hearts until he changes.
Numemon : Leave one heart for both hunger and strength until he changes.
Seadramon : I haven't tried this yet, I will post the method when I get one.
Tyrannomon : I haven't tried this too.
Metal Greymon : Get a Greymon, an Airdramon or a Darkmon. Battle with it for 15 times and at least must win 40% of it before he turns 10.
Mamemon : Get a Meramon, a Seadramon or a Tyrannomon. Battle with it for 20 times and at least must win 40% of it before he turns 8.
Teddymon : Get a Numemon. Battle with it for 12 times and win at least 40% of it before he turns 7.