REMEMBER, FORGET, REGRET and TRY can be followed by infinitive with "to" or V -ing. But there are differences.

  They are followed by infinitive with "to" when:

remember, forget and regret express the earlier action:

Remember to phone your brother. It´s his birthday.

  The action expressed by "remember" will take place first and then the one expressed by "phone." If the action expressed by "remember" is not carried out, the action expressed by infinitive with "to" will not be performed, either.

try means to make an attempt or effort:

He is trying to catch a butterfly.

  They are followed by a verb ending in -ing when:

the verb ending in -ing used after remember, forget and regret expresses the earlier action:

Paul can remember taking the key out of his pocked but he can't remember locking the door.

  The action expressed by "take out" happened first and now he remembers it. If he locked the door, it doesn't matter whether the action expressed by "remember" is performed or not, the action of locking the door was performed.

Compare:

 Robert did not remember to post the letter. (The letter was not posted. It is still in his pocket.)
(1st action = remember  2nd action = post)
 
June can´t remember posting her mother´s magazines but she posted them. (She can´t remember putting the magazines into the postbox but she did it and the magazines are not in her bag any longer.) (1st action = post  2nd action = remember)

try means to make the experiment (to do something in order to find out how useful, effective, etc., it is):

I haven´t been able to contact John. Try phoning his mother´s phone number. (phone his mother´s phone number and see what happens. He might be there.)

I don´t like natural yoghurt. Have you tried adding a little sugar to it?