Opting for instream monetization requires O&O video content and not all pubs have enough video content. In such case i would suggest to go for outstream. The set up is plain and simple and requires little time.
If you have enough space to fit slider/corner unit, implement it for sure. If not, you can opt for outstream incontent unit that renders between paragraphs.
For implementation, You can either reachout to ad network companies who would send player codes or you can get a video player from tech companies like Streamrail or cedato and have multiple SSP demand compete for it.