Theme development

I'm beginning to teach myself theming and I'm seeing a lot of stuff on different approaches. If I'm working from a design I created in Photoshop, what is the best practice for getting that layout setup in Drupal?. Is there a best practice, or set of requirements that would drive which way I chose to create it?

I installed flex slider for use with adaptive theme, i came to a issue when you set up image style to be used by flex slider, it always strech the image on 100% no matter what image ratio you set up.
Solution to show image in some aspect ratio.. for example 1024x300 px is to set up css of felx slider.
You go to /sites/all/libraries/flexslider, and change the line 26 to :
.flexslider .slides img {width:auto; height:auto; display:block; margin-left:auto; margin-right:auto;}

I downloaded a free theme called Colourise. It installed fine, but I decided I wanted to change the background image (bg.jpg). So I did so in the template files, using the same filebname, made the image the same width and about half as tall, zipped up the files again and reinstalled. Unlike with Joomla, which I have been using for little while, I discovered that Drupal won't let me install over the old theme, but instead says the theme is already installed. So I delete the theme manually over ftp, and reinstall with the new background image.

Override Admin theme CSS with hook_css_alter()

I am trying to alter some CSS settings in my Admin theme by specifying my own stylesheet. My admin theme is Seven and the site theme is a subtheme of Bartik. The site is configured to use the Admin theme for editing / creating nodes.

I used this tutorial and added hook_css_alter() to my template.php file:

Hello, I have a development site that I am using to test and work on a theme to upload to our production site. I have copied over the theme directory to the production server. My question is: do I need to recreate the views and blocks? I cant use backup and migrate to the new site because the content on the prod site is newer. Just making sure I am not missing a step. Thanks

I download and install a theme and want to test it by modify the code in the php and css file.
css files has no problem (it can immediately show me the change after refresh the webpage)

But the template theme file has nth change.
The downloaded theme has a "page.tpl.php" in its folder (it override the default one).

I remove part of the code as show below: