I always use salted butter, never shortening in my recipes. Shortening and vegetable oil can be substituted but if you've ever had my baked goodies yours will taste different. Unsalted butter gives my recipes an odd flavor (at least I think it's an odd flavor).
In all of my recipes I use X-Large or Jumbo eggs. If things aren't turning out as you would hope, check the size of the eggs you've been using, this sometimes can make a difference.
I use bleached all-purpose flour for my cookies without sifting. I've also had good success with Whole Wheat Unbleached All-Purpose Flour.with Chocolate Chip and Oatmeal cookies, but not with Snickerdoodles or Sugar Cookies.
Most of the time I use generic bleached all-purpose flour. With the exception of the Snickerdoodle (a.k.a. Satan) muffins, Whole Wheat Unbleached flour can be used, although it will make the muffins denser and heavier (something I do enjoy when making the fruit based muffins and scones).
For best results use King Arther's Whole Wheat Flour. It makes the quick breads denser and helps maintain the moisture. Yes, it's more expensive, but it's worth. I stock up whenever it's on sale.
I will note approximate measurements with any recipe calling for this, but truth be told I just mix up a bunch until it "looks" right. See the picture on my 12/17/12 blog post to get an idea.
I use Pam Baking Spray to grease my pans.
Lining Cookie Sheets:
I love Parchment Paper for lining cookie sheets. Not all non-stick cookie sheets are the same so I will often use paper to protect the cookies and the sheets. Plus it cuts down on washing.
Cookie Sheet Recommendations:
I love the Air Bake cookie sheets, but any will do if lined with parchment paper.
Muffin Pan Recommendations:
Always spray your muffin pans, even if they're non-stick. Paper cups will work as well, unless the recipe says not to use them.