Zechus was created in order to....

• Create a common project and goal that all Jews in the world can participate in.
• Create a platform that will motivate individuals to do good deeds and be able to track them
• Provide elevation to souls of Jews throughout history

Some people like a certain Tikkun and want to do it over and over for all the Niftarim of a cause and then when done move on and start doing that same TIkkun for a different cause. This is great but you do not have to do this you can perform any Tikkunim you wish and constantly switch from one to the other. You can also experiment and try doing all the Tikkunim listed on the site.

• Some members feel dedicated to a certain Cause or set of Causes and will constantly applying all their Tikunim there.
• Other members like jumping from Cause to Cause and applying Tikkunim in many various causes.
• Other members like doing Tikunim specifically for Causes on their Yortzite. 

You should do whatever motivates you the most to do good deeds.

Originally you had prepared yourself to do a specific Tikkun for a specific Cause but when you actually got around to doing the Tikkun you were distracted and forgot to have in mind that you are doing it specifically for the cause.

• Example: You had in mind to go to the Beis Medrash and learn for an hour in merit of the Niftarim of a Cause. But when you actually got there you started learning and the Cause totally slipped your mind.
• Example: You committed to refrain from all Lashon Hara at an upcoming wedding, in merit of the Niftarim of a Cause. However when you got there, the Cause totally slipped your mind and you just avoided all Loshan Hara because you knew you had planed on doing that.

Yes this is fine. Obviously it is better if you have the Niftarim and the Cause in mind while you are performing the actual Tikkun. However if at the time it slipped your mind, it is still very good since your initial inspiration and determination to do the Tikkun was in merit of the Niftarim of the Cause and so was the actual Tikkun that resulted from it.