When I trigger helm-swoop, it autofills the search with the word at point. For my most common use case, this isn't what I want. How do I disable it, so there's nothing in the search.
When helm swoop starts up, it looks at the variable
helm-swoop-pre-input-function. That variable stores a function that returns a string, and helm swoop uses that string as the default value. So, to not have anything in the search, make that value return an empty string:
(setq helm-swoop-pre-input-function (lambda () ""))
Its default value is to call
(thing-at-point 'symbol). There are more examples here. For example, to always use the previous search:
(setq helm-swoop-pre-input-function (lambda () (if (boundp 'helm-swoop-pattern) helm-swoop-pattern "")))