IrfanView is a lightweight and fast image viewer for Windows. Here are some settings to make it more useful.

By default, IrfanView will not jump to next image if you delete current one. To enable this, click Options --> Properties/Settings... --> File Handling. Under the delete section, check the following box:

When we are viewing images in a directory, it is annoying that window size chagnes as image sizes vary. To keep the window size and fit the image to window, go to View --> Display options (window mode) and choose Fit images to window.
By default, Irfanview will exit immediately if we press the ESC key when we are viewing an image, which is really annoying. To disable this behavior, go to Options --> Properties/Settings, in the popup window, click Start / Exit options. In the Exit options section, check the box Warning on ESC program exit. Do not forget to click OK button to save your settings.