Basics

Whatever you search, it has to be expressed so that the result is unique.

You can search for a specific piece of text.

Images can be found using their alt-text.

You can limit the scope by a path which "looks like" a hierarchy to the end user:
foo

sub header

foo

subsub-header

foo

In case all else fails, use data-uitesteri -attribute.

Labels and fieldsets

You can find a component with its wrapping label.
The label can be external to its field.

Fieldset legend can be used to limit the scope to the specific fieldset. input label

Form fields

Various kinds of form fields can be controlled.

You can limit the scope to an optgroup.
radio 1 label radio 2 label
checkbox label

You can type into a datalist, or click an option.
You can only type numbers to a number field,
write whole dates to a date field,
#rrggbb colors to a color field,
write a value to a range,
write yyyy-MM to a month,
write yyyy-Www to a week,

write a HH:mm/HH:mm:ss/HH:mm:ss.SSS to a time,
write a yyyy-MM-ddThh:mm:ss.SSS to a datetime-local,
type into an email,
a search,
a tel,
a url