1-I will not post a giveaway on my blog that requires you to follow, make a blog post of your own, twitter, etc. Those may be additional methods of entry (for bonus entries) but all giveaways posted here will have at least one basic entry method (either a form to fill in or a comment).
2- Most giveaways require that you either leave your email address in your comment (you can leave it in an alternate format such at kissyjensen at gmail dot com to avoid trolling programs from picking up your email address) or having your email address in your blogger profile (and that profile being set to public). They will need this in order to contact you if you are the winner.
3- Make sure that they say they will email the winners, some require you to check back and contact them if you are listed as a winner.
4- Following a blog that often offers product giveaways is very helpful in two ways. First, you will always be updated when a new giveaway is posted, and second, you usually get an additional entry in each of their giveaways if you are a follower (make sure you read the directions, and leave an additional comment saying that you are a follower).
Most of all, have fun finding new products! And don't forget to let me know if you win! I love to hear of others winning!