Nah invading and meeting no enemy sucks, it can just end up being a buff trade, now stealing an enemy buff while they are doing it is satisfying and effective. I feel that blue buff is much more important at the start then red buff for almost all junglers as the cooldown reduction is great and the mana regen is a must, red buff on the other hand doesn't do that much damage although the slow is great for ganks but not a requirement to do ganks so if you just steal the red buff it doesn't slow down an enemy jungler that much, they will lose a bit of experience but will probably have more health and can do ganks with less risk to themselves.
Invasions are risky but the payoffs can be great especially on low level games as players don't defend that well and people don't have flash which means if you meet someone while doing an invasion they have no escape and are easy to kill, higher level it can be less worth it but usually the reward outweighs the risk as long as it's not a late invasion.
It's assumed that when you invade, you ward your own buff. But, I guess this isn't a good assumption for all...
Invading and finding a team is far riskier. You have no guarantee that you can defend against the action, plus further lanes that are needed in order to properly and safely execute such maneuvers can be disrupted or even lost if they find enemies, as the enemies need only keep that lane from returning too soon. The risks do not outweigh the rewards most of the time.
This is assuming that you DON'T meet a team that is willing to fight you, either. Failing an invade has more negative consequences than succeeding one has positives, as not only do lose that buff, a number of teammates, but also morale, which can cut deep.
But, if we're just assuming that it's okay to use the maneuver because they're low levels, then that's the spirit on how to teach people what to do. Don't tell them the downsides, and just assume your enemy is bad! It is best to never assume your enemy's skill until you've seen their mistakes. Until that point, assume they are better than you. Worst case scenario, they are!
So, meeting NO enemy does not suck unless you really want to fight. It means you are either being watched, or you can snag a free buff. Heck, hopefully it means you can snag 3/4 buffs for free.
The best plan is simply... Don't do it. I have seen far more failed invades than successful ones, and even the ones that succeed incur some sort of issue arising from it, and losing the game. It's better to protect your own buff than try to steal the enemies.
Also, you're not entirely correct. While the CDR is great and the mana/energy regen can be beneficial, some champions simply do more damage with Red Buff starts. Red buff deals 12 damage per second at lvl 2, which can be much more beneficial than the blue buff for champions with HIGHER cooldowns, as their cooldowns are simply so high, they are only able to use their skills once or twice during a buff camp. Also, if mana or energy regen isn't something your character needs, it's not a bad start. I won't argue that blue is typically a safe and easy buff to start, but it doesn't necessarily increase your damage more.