well, here goes :
Opping concepts for dummies*
1) Ops are limited, so make sure you have several people able to do crucial ops. Most people dont have loads of op defenses, so an attacker with some useful ops and a good amount of oppers can actually do quite a lot of useful stuff allready.
2) Have specialists, with lots of the relevant oppers, and keep m in reserve. Yes, it seems counterintuitive to not use the best oppers you have, but keep these guys for opping targets that resist your other, less powerful oppers. Keep m for those ops that NEED to happen. This will increase efficiency, and by using the specialists less you also prevent big losses of oppers on freak fails.
3) Small specialists are better than big ones. Yes, the nw and planet count of the opping party compared to nw and planet count of opped party is a factor. When the opping party is bigger than the opped party, a penalty is applied. Mind you, when the opping party is smaller, they do not get a bonus. Still, a small resourcing pax is a lot more efficient at spells than a big popbanking one, coz they face penalties less often.
4) Freak fails. They happen. Unless you have an overpowering numerical advantage (10x the needed amount and more), quite often even. Doesnt matter that you have 3x the amount of oppers where you only need 2x the amount, you'll still fail. Its a game of chance, and every time you engage in opping (most definitely with such ops as hypno, estorms, portal ops and nukes, they seem to get more of these than other ops) you expose yourself to losses. Nothing to be done about it. Calculate it in before you start.
5) Use your ops wisely. Seems logical, but still people seem to do a lot of just-for-the-heck-of-it opping. Consider the long-term effects of ops in a war, and how easy they are to pull off. Depopping a big popbanker might seem like a lot of fun early in a war, but you can bet your ass he has a ton of wizs, and maybe your attackers need some portals down too, and in the long run it'll pay off more to keep their attackers at many ticks from your planets than to hamper their cashflow early on. Maybe you can more easily hamper their income by depriving them of food by casting reduce food production on their easier-to-hit farmer. Do the crucial ops first, and the fun and/or frivolous ones later. Smart fams most often have paxes cpff enemy attacker portals to hamper their attacks, and deprive popbankers of pop by having attackers raiding their planets, instead of having paxes depop bankers and attackers bust other attackers' portals. Its all about the losses vs the gains here.
Hope that helps 
*1: no im not saying YOU are a dummy crioz, this is a quite normal manner of introducing concepts to the less-informed
before we get into yet another shouting match 
*2: this is opping CONCEPTS for dummies, not opping for dummies. It allready supposes that you know what ops do, which oppers do which ops, how the slider works and so on.
When speaking your mind, it is of utmost importance to keep using it !