How to store transactional information on the blockchain I have an operational process that involves several sub processes. I am currently maintaining an audit trail of the entire process. 

For (successfully) completed processes, I want to record the successful transaction (along with all relevant details) on the blockchain, for public consumption. 

What is the 'best practise' way of storing data on the blockchain? - and what (if any), are the data size limitations (and how to workaround data size restrictions?)
OP_RETURN is meant to store extra data on the blockchain. As fees are per kbyte, you'll be paying more fee.

Remember that block size is limited (1MB now every 10 minutes, but growing) and fees are expected to go up quite a bit, so if your application needs to be able to scale, you really need to do some calculations whether yours is a viable solution at all (in general: it should be much cheaper and easier to store extra data yourself, instead of burdening the whole world with it).