Do Little...Better than Nothing...

Al Salam Alaikum wa Rahmat Allah wa Barakatoh

One saying of our Prophet -Salla Allaho alaihi wa Sallam-:

"أحب الأعمال إلى الله أدومها وإن قل"

This means that the best doings or actions that Allah likes the most are the continuous ones, the ones that never stop even if they were very little or minor good doings. 

E.g. when someone will perform "Doha" prayer, which is one of the sunnah prayers more than the five daily obligatory ones, to be performed seeking more rewards of Allah - I'll talk about these rewards maybe next time inshallah-, this prayer can be done by performing only two "raka's" and we can increase the number of raka's and pray until twelve or more as much as we want. 

So, if you prayed two raka's only but on daily basis, this is better than praying twelve raka's today, then you don't pray any Doha prayer the rest of the week.  Given the fact that, there are no real excuses of sickness or whatever that didn't allow you to perform your regular worshiping.

Another example might make this clearer, when someone fasts three days a month, which is one of our Prophet's advice for us, this is better than fasting every Monday and Thursday but for only one month, yet, not fasting any other days the rest of the year -of course except fasting the holy month of "Ramadan"-.  I wish that this is vivid and clear for everybody, if not, please excuse my humble way of elaborating. 

 Hence, don't force yourself to do any kind of regular sunnah worshiping in large quantities, if I may say, if you are not sure that you would be able to keep on doing that for the rest of you life.