I wrote 2 posts on how to enter giveaways and I thought it would also be useful to write one for bloggers.
Be clear when you write your entries. For a mandatory entry, try not to ask people to subscribe to your blog via e-mail, let readers subscribe only if they want to. For bonus entries, be clear how many entries each one. is worth. If you ask to follow on Twitter, make "Twitter" a link to your Twitter page. I've entered giveaways where I couldn't find links to Facebook and Twitter pages anywhere!
Set up clear rules. When the giveaway ends. Age/Country restrictions. How the winner is chosen (usually through random.org). How long winner has to respond back.
Disclose whether you have been compensated or received items for free. Takes a second, but will save you any trouble later on. I'm not too familiar with policies and why it's important, but from what I understand it is some kind of an internet policy. If anyone has more info on this, please share.
Who can enter the giveaway?
As a Canadian blogger, this is one of my biggest pet peeves. 4 out of 5 blogs do not specify in the rules who the giveaway is open to. Thus thousands of people like me, avoid these giveaways. If you want more giveaway entries, you need to specify who can enter - US, Canada or Worldwide.
(I get lots of giveaway advertising comments on my blog and most of them are begging me to enter, because no one else is entering. I would love to enter, but when I go to check out the giveaway, there are no country restrictions - therefor I leave the page upset.)
Prepare a text for tweeting yourself. It takes a second and your giveaway will be properly advertised. It also makes it easier for your readers as they won't have to make one up.
Notify winners through e-mail. I don't enter giveaways on blogs where they don't notify you. Most people don't have time to read every single e-mail they get.
After your get the winner's response, let them know that you received it and sent their info off to the sponsor. It takes a second, but lets the winner know that you care. I've won numerous big prizes and never heard from bloggers whether they've received my e-mails or not. Thank God I've received the prizes, but I did worry a lot!
Most people want to see how winners are chosen. Displaying random.org screenshot is the easiest way to show you winners. Or at least list the name and a comment number. I've seen blogs which don't list winners at all and readers have no idea if anyone even won.
EVERYONE complaints about Captcha on Blogger and wait times on Word Press. Yet every second blog I visit has captcha enabled. I (and many others) avoid such giveaways, because it takes up a lot of time to enter them and most of us with babies - don't have extra time.
Blogger people - have comments list under the post and disable captcha. Pop-up comments are annoying. Even more annoying is when captcha appears after you hit "submit comment". To disable captcha - go to Settings - Comments. For "Comment Form Placement" select "Embedded below post" and for "Show word verification for comments" select "No". If you also select "No" under "Comment Moderation" - everyone will thank you, I promise!
Word Press people - there is a simple plug-in which will turn off comment wait times. I don't have a link since I'm not on Word Press, so if you know where it is - let me know. I'm sure it's easy to find! Also, if you don't limit your comments per page to about 200, it takes forever to load 1000+ comments and my browser often crashes.
I don't mean to sounds harsh, I'm simply being honest, voicing what I've heard from many people and also trying to help you make you blog more successful.
Same as in "Who can enter the giveaway?", as a Canadian I find Giveaway Linkies absolutely useless. I love to advertise giveaways and get many visitors that way, but I can't enter anything. NO ONE puts down who the giveaway is open to. I can waste my time clicking through links to find Canadian-friendly giveaways or I can not click at all. So please write down the countries and you will get more clicks!
(I tried hosting a linky where it is mandatory to write down who the giveaway is open to and 9/10 people did not follow the rules. No matter how large and bright I made the font.)
P.S. OMG I hit 1000 followers :D *Off to celebrate with a cup of tea*