it's all down to experience, and it really does take years to know when, where, and what state of the tide, and which way the wind is blowing ,what time of year it is, do i fish it during a big blow or after, what is the best type of bait for that time of year, what type of rig would be the best etc etc and I'm only scraping the surface here, sea fishing is not just chucking a bait into the sea and hoping for the best