This is best used with a few recent Clipboard entries, not say 10+ of them, you would probably not be able to remember those
A scenario, using my below example with <a href>:
I know I am going to add to my list of useful websites a new entry, consisting of the URL, the page name and a short description. I copy these three text variables from the webpage into the clipboard (in this specific order, so that the URL is the oldest variable and the description the newest) and then use the pre-prepared button in TypeItIn to combine and paste the last three Clipboard entries into a single combined entry.
The prerequisite here is of course remembering the correct order of copying relevant entries into the Clipboard, so that your result is not mismatched. But for example at work I use TypeItIn/ArsClip for many repetitive tasks and text-entries, where they are already ingrained in my brain, so I know the order to copy the source entries in.
Another example would be filling out a form, consisting of personal details about a person copied previously (Name, Surname, Date of Birth, Social security number, Address, Occupation...), where TypeItIn can be used to Paste-TAB-Paste-TAB-etc. through it, using the recent Clipboard entries.