Dialyzer is a great static analysis tool for Erlang and has helped me catch many bugs related to what types I thought I was passing to a function versus what actually gets passed. Some of the errors Dialyzer emits are rather cryptic at first (as seems commonplace in the Erlang language/environment in general) but after you understand the causes of the errors, the fix is easily recognized. My most common error is Dialyzer inferring a different return type that what I put in my -spec, followed by Dialyzer telling me the same function has no local return. An example:

foo.erl:125: The specification for foo:init/1 states that the function might also return {'ok',tuple()} but the inferred return is none()
foo.erl:126: Function init/1 has no local return

The init/1 function (for a gen\server, btw):

-spec(init/1 :: (Args :: list()) -> tuple(ok, tuple())).
init(_) ->
  {ok, #state{}}.

And the state record definition:

-record(state, {
  var_1 = {} :: tuple(string(), tuple())
  ,var_2 = [] :: list(tuple(string(), tuple()))

Spot the error? In the record definition, var\1 is initialized to an empty tuple and var\2 is initialized to an empty list, yet the spec typing for the record does not take that into account. The corrected version:

-record(state, {
  var_1 = {} :: tuple(string(), tuple()) | {}
  ,var_2 = [] :: list(tuple(string(), tuple())) | []

And now Dialyzer stops emitting the spec error and the no local return error.