Product Category and product details meta tagging

[GFORCE75]

After a lot of reading on google Im still at a loss as to the importance to the meta tagging (titles, descriptions and keywords) on the categories and products.  Should I add these in as I go along, how important are they these days?  Also I hear that there is a plug in that can do this for me.... is it more practical time wise to do it as I go along or just ignore them and then get the plug in and let it do it for me at the end.... how long would the plug in take to meta tag everything and how good are they at doing this??.

[Maxim Pishnyak]

Manually adjust your Title and Description.

[GFORCE75]

So you recommend adding manual information on title and description for all categories and products as opposed to getting a plug in?

[Maxim Pishnyak]

Yepp.