A Question About Give Aways

I’m plotting and planning a give away for my 30th Birthday in November.  And I’d like to make it a really good one!  I think I know what I’d like to give, and plans are well underway, but I would also like a bit of feedback on the process.

It’s common to see give aways that have entry criteria: you need to become a follower, or link back to the post on your own blog, for example.  Some of which mean that you get multiple entries.  Does this ever put you off entering?  Or do you like the option of having more than one entry?

What is a reasonable timescale to have a giveaway open for?  Is a week about right, too long or too short?  If there’s a multiple of a giveaway, would you prefer that you express a preference in your entry comment, or have a separate post for each item.  And should they run at the same time or one after the other?

I’m really hoping that what I’m planning will be exciting and something that you’d like to receive.  But sometimes the process is just as important, so I’d like to make that as enjoyable as possible too.  Any opinions you’re willing to share, advice or information you have on running a give away too, would be really useful.