Videos:
   Peacock Courtship
    Red-capped Manakin Courtship
   Bird-of-Paradise Courtship:  http://www.youtube.com/watch?v=W7QZnwKqopo
 

                                Motmot, Palo Verde, Costa Rica, April, 1985.  © James Adams, 1985
The male (pictured here) uses the feathered sections at the end of the tail as an attractant for females.  It will cock
them side to side (see image below) to provide a more obvious signal to the females.

Male Motmot, with tailed cocked, Palo Verde, Costa Rica, April 1985.  © James Adams, 1985


                                Parnassius butterfly, Rocky Mountain National Park, Colorado © James Adams, 2003.  The males of members of this genus
place a sphragis on the female after they mate (see below).  This prevents other males from mating with the female, so the male has complete
sperm precedence, fathering almost all of the eggs of the mated female.  This is, in essence, a "chastity belt".


                              Female Parnassius mnemosyne, with sphragis plugging mating passageway.  Just so you know
                            butterflies mate and lay eggs through different openings, so she can still lay eggs!!  © Lars Andersen, 2009
The sphragis may actually break down over time, though it takes a while.  So another male might mate with her, but by that point, she may be "old"
and have few eggs left to fertilize.

          Damselflies, male above, female below.  Male deposits own spermatophore in pouch on the underside
         of the second/third abdominal segments (orange in this species); convinces female to mate and uses
         claspers at end of abdomen to grab her behind her head; she then reaches forward with the end of her
         abdomen to retrieve the spermatophore.  This is a roundabout way of mating to say the least.       
                If you ever DO see a male damselfly apparently mating the "normal" way (end of abdomen to end of
         abdomen, then that male is actually scooping out the previous male's spermatophore. 
                ©animals.nationalgeographic.com

    Hangingflies mating; https://www.whatsthatbug.com/2010/11/16/hangingflies-from-australia-courting-and-mating/
This image shows the female feeding on a rather large fly that the male used to attract the female to mate.
The larger the prey item offered to the female, the longer they may mate (as she feeds, providing nutrition to her
eggs).  This allows the male to monopolize the female for the mating time, and give his sperm a head start on
fertilizing her eggs.  Large males tend to be able to obtain larger prey items, though some species steal prey
items from spider webs.  As such, large males tend to have an advantage, which is appropriate because this is
an indicator of their actual fitness.

  Stalk-eyed fly, La Selva, Costa Rica, March , 1985.   © James Adams, 1997
Females of stalk-eyed flies have selected for males to have long eye-stalks;
apparently, being able to get resources to build these stalks is an indicator
of the fitness of the individual males.