Order of Upgrades: What do I upgrade next?

I have a few ideas on the order of what needs to be upgraded.  Most of us agree that everything needs to be upgraded before moving on to the next town hall level.  But the question that I get most, is "Smack (my CoC username), what should I upgrade next?  Should I do the archer tower, cannon, wizard tower, barracks, etc?"  Well here is the order that I like to do things:

Laboratory

Upgrade your laboratory very first, as that will unlock higher level troops, and allow you to attack more efficiently, and get your troop upgrades completed sooner.

Splash Damage

I always upgrade my splash damage defensive buildings first.  Splash damage is for wizard towers and mortars.  What splash damage is, is the ability to damage many troops in a small radius.  When the mortar shot hits the ground, it damages every troop around it, and is effective in taking out goblin groups, or archers.  Wizard towers are the same, but can't attack as far.  This is why you need to evenly space the wizard towers and the mortars, so that you can cover everywhere (check a previous post to see how to layout a base).

Single Shot Damage

I next upgrade my single shot buildings.  Single shots are for archer towers, cannons, air defense, and hidden teslas.  However, I don't include hidden teslas here.  Archer towers and cannons are great for taking out giants, hog riders, and other stronger troops.  Splash damage combined with a single shot are very effective.  Many times, the mortar (which takes a long time between shots) will hit its target once, then miss on the second shot, and not take out all the troops.  Well once the mortar has hit the troops once, a single shot will almost always take out the troops with one hit.

Hidden Teslas

Lastly, I upgrade my hidden teslas.  I don't find these extremely effective, but they are nice to have around to pick off troops here and there.  Hidden teslas die easy, and there are a variety of ways that people have their bases set up to use them.  Hidden teslas attack P.E.K.K.A.'s with twice as much damage, and I haven't been attacked much with P.E.K.K.A., so I can't say much about them yet.

I have 5 builders, this is what I do with them:

2 builders on splash damage buildings

2 builders on single shot buildings

1 builder saved for walls, barracks, gold mines, etc.

When I had 4 builders, I had this order:

2 builders on splash damage

1 builder for single shot

1 builder for walls, barracks, gold mines, etc.

When I had 3 builders, I had one on each of the above points.

Here are some more tips and tricks I use frequently:

You should always have a builder busy.  If there is a time when he isn't busy, save quickly, and find something for him to do, even if it's out of order.

You never want to have more than 1 barracks being upgraded at a time, that slows down your progress on trying to save loot considerably.

On that note, don't upgrade all of one building at once.  For example, don't upgrade all 3 of your mortars at the same time, this will be bad because ground troops will dominate when attacking.

Keep your laboratory constantly upgrading troops, don't have down time with that building if possible.

You want every building upgraded, or being upgraded (a builder is working on it) before you start your town hall upgrade.  You also want to have half or so walls maxed before starting your town hall upgrade.  The other half you can do while the town hall is being upgraded.

***The above ideas are just ideas, if you find something that works better for you, go for it.