A Thread Counter and a Children's Magnifying Glass
to show that you can use whatever is in your household

The orange Magnifying Glass actually belongs to my Daughter
And I added it here to show that you can use whatever is in your household. You do not need to buy special loupes to start inspecting watches. Of course if you start working with watch movements, you will need watchmaker's loupes. The small black loupe is a thread counter for inspecting fabrics. Another example that you can use whatever is magnifying.