Creating a Segment with a combination of filters.
If there are combinations of filters that you use often, you can save them as Segments so you don't have to repeat the segmentation process every time.
E.g., you often target bloggers that are into architecture. Instead of applying the filters every time, save a Segment that combines media type 'blog' and tag 'architecture'.
The good thing about Segment is that it is dynamic, meaning that whenever a new contact is added to your database and he/she fulfils the conditions of a particular segment, he/she will get added to the segment automatically.
Creating a more static list using tags.
There are also cases when you might just want to create a static list of contacts, i.e. the list won't change when new contacts are added to the database unless you manually add those newly contacts to the list as well.
For example, you want to send a follow up email to everyone who has clicked a particular email. You can do so by adding a temporary tag.
Access the Campaigns page, access any campaign report, you wish to create a static list from. Navigate to one of the tabs on the campaign report (Clicked, Open, Delivered, etc) based on the list of contacts you want to create.
On that list, select the contacts, and use the button Apply tag.
This will add a tag to all the contacts who have clicked your email. You can name your tag as something like Temp_ClickedEmail123 so you will remember to remove the tag after sending the follow up email to keep your list of tags clean.
You can read more about adding tags to contacts.