Cameron Moll has written a great article about the fundamentals of web design. The overall idea behind the article is that there are certain formulas, or practices, that are better than others. As creative as a person would like to be, sometimes using a formula from someone else is a fast, easy, and ultimately better solution. Cameron refers to this process as stealing, with good reason, but these can be adapted to all types of web design. There are three levels of stealing according to Cameron.
Level 1: Copy, don't create. Taking the time to look at a site, figure out how they did what they did, and adapt other peoples techniques to fit your purposes. They used the example of taking the design of a Nike site, and using it to make their own page. They made changes, but they do look incredibly similar. It worked for both sites, and they saved a lot of time and energy in making their page.
Level 2: Steal from yourself. In this portion, Cameron talks about using previous work that you have done, and incorporate the code into a new site. Though this practice does me no good (I have created one site, and it is nothing to really be proud of), I think the code I have done previously will give me an idea about good structure, and something to check my work against to see if I am progressing or not.
Level 3: Steal from discreet sources. This means looking for things that are not mainstream, and try to find something to incorporate into your own work. The example used was someone took some random clip-art design, and created a logo from this. This seemed a little more risky to me, because if it gets big enough, someone, somewhere, is going to try and sue you for a copyright (even if they know they wont win.) I understand why people do this, because there are some great designs that people have no idea what to do with, but I just don't want to involve myself in this practice if at all possible. I would rather spend a more time making something than worry about the legal implications that might accompany this practice.
From the perspective of usability, I like Cameron Molls thoughts on stealing. If the navigation on a site works, there is no reason you should try to imitate/copy that workflow. To me, its kind of like building a house; A lot of houses share similar design and placement of things (toilets go in bathrooms, beds go in bedrooms, etc...) because it just works. Not every house is identical, but there is a logical placement of rooms and items (In good homes that is). so it is with web design. You don't have to have a site that looks just like apple.com to have a good website, but you may want to look at how the information flows, so you can imitate that experience and make your users feel more comfortable.
I found this article to be very helpful, and will help me as I try to actually make the design of my pages. This article talked specifically about webpages, but can be used in a just about any field. As for implementation, I will use other pages as references, and look at some of my old stuff to see how I had done it in the past.
http://articles.sitepoint.com/article/copy-great-designers-steal