"Constructor game" for web programmers?

Question

Web development

It may not be a secret that 99% of the pages are similar to each other, namely, the site header, block layout, form layouts, registration system, authorization, etc., for this reason it is easier to use your own developments, therefore:
1) Where do you store your snippets?
2) How do you implement them in your projects? ctrl + c & ctrl + v, or have you created your own cms to automate this?
3) Which ones do you use the most?
4) How much did it speed up your development?

Answer 1

for this reason, it is easier to use your work

no, that's why there are things like composer, npm and bower.
As well as frameworks, which are actually expanded by the above tools in any direction.
For "completely" their own: gist, github/bitbucket, hard drive.
Writing your bikes in native code (applies to php pieces without any basis in the form of a framework) and dragging them into each project is too cumbersome and harmful in the presence of modern tools.
It is not harmful only in the case when you make some kind of landing pages where one form goes to the mail.
In other cases, these are pieces of code without support and without, most likely, normal design. That complicates support to other developers.