I saw this question about finding new transactions.
But how do you pick which transactions to include in the block you're trying to add? Should it be in a certain order, or random? How many transactions should you include? Looking at the blockchain I've seen anywhere from just a few, to hundreds. Is the number of transactions something you'd vary when pool-mining to combat exhausting all possible nonces if up-to-date with the timestamp header? (Loosely related to my other recent questions).