We would be travelling to Croatia in the first week of August, 2015 and are wondering if it is better to exchange Euros to Kune in Germany or get Kune from Croatia itself. If in Croatia, which are the places that would provide the best exchange. If I take the exchange from Germany, I would probably go to the bank where I hold an account for exchanging Euros to Kuna. Could someone advise which one is more advantageous.
Following the simple economic principles of supply/demand and cost of transporting currency I'd say your best bet is to exchange your currency in any touristic town or somewhere around Slovenia/Croatia border, but not right on the border, where there is usually only one exchange office. At least that is what I've always done.
And yes, you should stick to exchange offices, those usually do not charge any exchange fees while giving better exchange rate than a hotel.
Always check current exchange rate on the internet and then compare it to exchange offices exchange rate. Exchange office's exchange rate must be published by law and any touristic town has bars with free wi-fi, so this can be accomplished quick and easy.
If you're from Germany, I would recommend using a credit card at an ATM (cash machine) in Croatia.
Currently (checked 2016-07-11), Consorsbank and DKB don't charge any fees when using their VISA card with at any ATM worldwide. There may be more banks that offer similar rates, but those two I know of.
I'm using a giro card and credit card from comdirect. But as far as I know my experience is generalizable. My report is referring to our vacation in Croatia in June 2016.
Paying with giro card and credit card will come with a fee. You will also have to pay a fee for fetching money from an ATM using the credit card.
What we did was fetching money on ATMs from reputable banks (f.x. Splitska Banka) using our giro card (EC card) - also check for signs of skimming.
The trick is that this will not come with a fee! At least not at those ATMs we used. If there is a fee (absolute and relative) then it should be displayed.
But you will be asked whether you want to use a guaranteed exchange rate (of about 7.1 Kuna per Euro) or one that is not guaranteed. Incidentally this rate was throughout our trip around 7.5 Kuna per Euro. That's pretty much the direct exchange rate. 
Following this advise will allow you to fetch money in Croatia as needed at an optimal exchange rate and without having to pay a fee. Also I felt more comfortable with this option opposed to using my cards in random restaurants and shops.
: The information about this "scheme" we got at the airport right before going to Croatia from the Finanz Test magazine 06/2016. The link below seems to hold the same content while being from 2014