invest into automated tools and infrastructure that will ensure that all of your image assets are always optimized

You will want to read this...
How To Use Images To Increase Search Engine Ranking

Find broken links on your site with Xenu's Link Sleuth (TM) to crawl the pages, download them in excel and then create some "easy" formula to create relevant content example:

Profession + Name of City +Review/evaluation/warning

And then original text

I would suggest you to do this manually. First of all make an excel sheet and write down all the image alt tags in front of the images and then implement it, this will lessens the risk of missing any image as well as doing any mistake.

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You can do by saving images with your keywords and submitting to various websites like imgur, picassa, pininterest and many more.

And dont forget as well to do an Image sitemap, that will help you A LOT.

File naming convention, alt tags are the prime method for image optimization. Apart from that image resizing is another great way for the image optimization.

you can also automate your website

I just do it manually, whenever I insert a new image on one of the websites I own. I don't even know of any 'special techniques' other than writing the tags &description myself.

All this stuff & nobody has mentioned the single strongest image ranking factor that trumps everything combined in this thread.

Yes alt tag is better for picture and search engine.