Not adding citations: This is the most commons mistake in Wikipedia. Encyclopaedic content must be verifiable. So, please add citations while adding or changing information. See
WP:RS,
WP:V and
Help:Cite for more info.
'Uploading copyvio film poster, DVD cover, book cover: The Wikipedia uploading process is so complicated that new editors often do not understand that the "actually" can upload non-free images of contents like film poster, DVD cover, book cover etc and they end with uploading copyvio images at Commons. Note, images of living people can not be uploaded under fair use. Please expand this point
Adding Indic scripts in lead/infobox: We should not add Indic scripts in WikiProject India articles. See
User:Sitush/Common#Scripts for details.
Not following WP:ORDER: The correct order of sections should be "See also">>"References">>"External links". See
WP:ORDER for more information
Overlinking: In an article one link should not be added more than once or twice. See
WP:OVERLINK.
Five more
Remember Wikipedia is not the place to right
great wrongs.
Not assuming good faith:
Assuming good faith (AGF) is important. You may find yourself involved in heated discussions on articles concerning things such as caste and politics, or even names for things: it is best to assume that those who disagree with you are doing so due to genuine concerns rather than because they are "anti" you, your caste, your politics or whatever. AGF is not a
suicide pact but it should be the default position unless you have strong evidence to the contrary.