app/views/devise/sessions/new.html.erb
<% content_for :title do %>
<h1 class="project-banner space-below">
Sign in
</h1>
<% end %>
<%= form_for(resource, :as => resource_name, :url => session_path(resource_name), :html => {:class => "form-horizontal"}) do |f| %>
<fieldset>
<div class="control-group">
<%= f.label :email, "Username or Email", :class => 'control-label' %>
<div class="controls">
<%= f.text_field :email, :class => 'text_field' %>
</div>
</div>
<div class="control-group">
<%= f.label :password, :class => 'control-label' %>
<div class="controls">
<%= f.password_field :password, :class => 'text_field' %>
</div>
</div>
<% if devise_mapping.rememberable? -%>
<div class="control-group">
<div class="controls remember-me">
<%= f.check_box :remember_me %> <%= f.label :remember_me %>
</div>
</div>
<% end -%>
<div class="form-actions">
<%= f.submit "Sign in", :class => "btn btn-primary" %>
<%= render "links" %>
</div>
</fieldset>
<% end %>