[Narada93]

Is hard resetting my Lumia often is a bad thing? With the heavy usage I believe my lumia 625 becomes much slower than how it was earlier. Maybe because the storage gets filled up and maybe temporary files eats more space. So is resetting my Lumia more often to freshen up the phone is a bad thing to do? does too much hard resetting cause any hardware or software problems?

[Harrie-S]

The answer is not a straight yes or no.
1 It will not create hardware problems.
2 It may create software problems but this depends on your definition.
If you do a hard reset and after that you install everything manual than no problem are to be expected. If you restore the backup that may give some problems if the backup was not up to date.
3 If you run out of battery during the hard reset you may brick your phone.

But a hard reset is not needed every 3 months.

What you can do is delete IE history and temp files with storage sense.
Low storage space will cause some lag. So if you have only around 500 Mb left get an SD card (class 10 from a well known brand).

Conclusion.
There are better ways than a hard reset to keep your phone crispy.