Some of the nice components I’ve seen included the ability to sum calculated values from arrays where the method is accessing the ActiveRecord fields on the same object.

def sum_invoices
 invoices.to_a.sum(&:invoice_total)
end

Also I have been working with HAML after being introduced to it by one of the team and while it does take me back a little to all those Java templating languages and I now see how useful it is in pushing people toward using CSS.

Other nice little features I have been picking up on include using ruby in fixtures which includes being able to create large number amounts of test data.  As I get more into it the rewarding part the pace of my development appears to be picking up :)