Did you know about the Global Brand Database from WIPO (the World Intellectual Property Organization)?
You may have been familiar with TESS, the trademark database from the US PTO. The advantage of using the Global Brand Database is to expand the scope of your trademark investigations. Even if you are just interested in one region or country, you can still leverage the WIPO database.
Like TESS, the Global Brand Database is free! It is free to search BUT if you want to save your searches, you will need to create a WIPO account. With a WIPO account, you can use the same account to save your searches on patents (PatentScope), trademarks (Global Brand), etc.
So whatever the reason you're searching for trademarks, the Global Brand Database should be in your toolbox!