user57563: Let's say I run an automated script, with the main purpose to send transactions as fast as possible. 
I want to send one transaction with 5 BTC to one address and a transaction with 2 BTC to another.
My own bitcoin wallet has 2 transaction inputs, one with 3 BTC and one with 7 BTC. 
How do I spend the transactions the fastest way?

Spend the 5 BTC first having 7 BTC as input, get the change of 2 BTC returned and send this 2 BTC to another address.
Spend the 2 BTC first with 3 BTC input, spend 5 BTC with 7 BTC input.

Does order actually matter if I want to send transactions as fast as possible? I was assuming that due to the confirmation time, an optimized transaction order will have an impact on speed of the transactions.

user3511: 
I want to send one transaction with 5 BTC to one address and a transaction with 2 BTC to another.

The fastest (and cheapest) way to do this is with a single transaction.
Many transactions have 2 outputs, one being for change, but it doesn't need to be for change, and doesn't need to be limited to 1 or 2 outputs either.
Take this transaction for example, it has about 2 dozen outputs: https://blockchain.info/tx/df9ba42c44d25df13d3bdba0994b98b97d8c22293daf0c27e8e5d9b4e21c5906
 
Total fee, just 0.00483272 BTC

57563: <p>Let's say I run an automated script, with the main purpose to send transactions as fast as possible. </p>

<p>I want to send one transaction with 5 BTC to one address and a transaction with 2 BTC to another.</p>

<p>My own bitcoin wallet has 2 transaction inputs, one with 3 BTC and one with 7 BTC. 
How do I spend the transactions the fastest way?</p>

<ol>
<li><p>Spend the 5 BTC first having 7 BTC as input, get the change of 2 BTC returned and send this 2 BTC to another address.</p></li>
<li><p>Spend the 2 BTC first with 3 BTC input, spend 5 BTC with 7 BTC input.</p></li>
</ol>

<p>Does order actually matter if I want to send transactions as fast as possible? I was assuming that due to the confirmation time, an optimized transaction order will have an impact on speed of the transactions.</p>
 3511: <blockquote>
  <p>I want to send one transaction with 5 BTC to one address and a transaction with 2 BTC to another.</p>
</blockquote>

<p>The fastest (and cheapest) way to do this is with a single transaction.</p>

<p>Many transactions have 2 outputs, one being for change, but it doesn't need to be for change, and doesn't need to be limited to 1 or 2 outputs either.</p>

<p>Take this transaction for example, it has about 2 dozen outputs: <a href="https://blockchain.info/tx/df9ba42c44d25df13d3bdba0994b98b97d8c22293daf0c27e8e5d9b4e21c5906" rel="nofollow noreferrer">https://blockchain.info/tx/df9ba42c44d25df13d3bdba0994b98b97d8c22293daf0c27e8e5d9b4e21c5906</a></p>

<p><a href="https://i.stack.imgur.com/l0U4A.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/l0U4A.png" alt="Trnasaction"></a> </p>

<p>Total fee, just 0.00483272 BTC</p>
