EHM The Blue Line

So, I have this question buried in my mind for ages: When is the best time to scout the Draft? For reasons I do not understand it is not possible to scout this key feature permanent, so I usually send scouts on a 3 months job. And I do this 3 months before the draft, bearing in mind the results will be lost if I re-send them. So somewhere in March I apply 5 scouts to the Draft.

But is this the best way, does it make sense?

I usually have scouts out on different regions, nations and leagues well in advance. That way you can discover other players, too.
Once the trade deadline has passed I send my top scouts on the draft itself.

I personally scout the draft every time the rankings show up. For no other reason, than the one Satyr mentioned, because no permanent scouting option is available, these mid / late / etc season rankings are a good reminder. I'm assuming many scouting trips is better than one, so why not repeat the process.

I send the scouts to the NHL draft 3 times per year on intensive, I try to match them with the ISS rankings so I have my first batch of scouting for the Preleminary ranking, then another at the mid-season and a final one for the final ranking. I try to scout ALL of the players who were ranked (even if they were only ranked once and not anymore) Also send your scouts to the Canadian Juniors and a few European Leagues on permanent.

One quick tip for drafting, look at Poise in the report card. I usually find gems with Poise of B+ or more, there's a ton of good players in the 7th round still.

All these suggestions are good ones. And another one that can't be overlooked is by starting as early as you can. Sure in the first few seasons you're mostly focusing on the kids closest to getting drafted, but as time goes on you want to be scouting those 13/14 year olds that are generated every season, so that 3-4 years in advance you'll have a good idea who can become good and who won't, and in time that will mean you'll end up finding gems lower down the draft order who you can pick up.

Also as Axepig suggested, try to look for stuff like poise, and also hard workers in general when you're going lower in the draft. You might not pick up the next Connor McDavid that low, but there are a lot of good/great 3rd or even 2nd liners down there that work hard and might end up improving a whole bunch, perhaps blooming later.

Good tips are always to station at least a few scouts in the big hockey nations (USA/Canada/Czech/Sweden) that are only focused on scouting u17s or u16s, that way they won't 'waste' their times on older players that are also based in those nations. You can also scout smaller nations like Switzerland and Austria, and you can find some good gems there that are often overlooked in the NHL/Import drafts, but it's also all about having your net over an as wide as possible area, since in EHM:EA there's a limit to how many scouts you can use.

And finally, unless you manually order every player in the draft to be scouted, you won't be able to really know about everyone in the draft. There's always players that slip between the cracks.