Fluorescent ballasts produce heat.   The heat that is dissipated costs you money in two ways!

Incadescent lamps are the standard light bulb.   Fluorescent lamps save considerable money in operating costs.   They cost more but they have a short payback period.

A 15 watt fluorescent lamp produces the equivilent of more than 60 watts of incadescent light!  The average life of a fluorescent is 10-13,000 Hours!   That compares to 750-2000 hours for an incadescent lamp.

Dimmers save you money in two ways!   First, by the fact that you have the light level set lower than it would be if there was no dimmer installed, saves you money by using less electricity.

Some dimmers when turning the brightness up will go from off to full on and then as you continue turing or sliding the control will dim.   This type dimmer still gives the lamp a "shock" as soon as you turn it on.   That's the problem with a regular switch.   The shock to the lamp element going from off to full on is usually when lamps burn out.

The dimmers that "gradually" go from off to full brightness will make your lamps last much longer by NOT giving the lamp as great of a shock as a regular switch.

So, you want to make sure your dimmers when turned on will go from "off" to "dim" then brighter as you turn or slide the control.   This type dimmer will greatly increase the life of lamps.

Timers CAN save you money.   But,

Attic ventilator fans may or may NOT save you money!

Air conditioner efficiency is of great importance.

If you frequently blow fuses or trip breakers, it could be a sign of a problem.   If the fuses and breakers are sized correctly for the wire size being used, they should never blow or trip unless there is a problem with an overload or short.

Many older houses have a fuse type panel with a main, a pull-out for a range and 4 other plug type fuses.   This means besides the range you have only 4 - 120 volt circuits to feed the rest of the house!   Some of the newer homes have breaker type panels that do not have enough circuits either.  Especially if you consider the following needs to be on its own circuit...

Range, Oven, Refrigerator, Dishwasher, Dryer, Air Conditioner, Spa, Garage Door Opener, Icemaker, Hot Tub, Microwave, Disposal, Well Pump, in addition to these circuits, you must have "at least" two small appliance circuits for the kitchen and one circuit for GFI outlets in the baths.   This is not a complete list of items that need to be on their own circuit.

Lots of panels have more wires than fuses or breakers.   For example, if someone added an outlet for a air conditioner, they would run the wire from the panel to the air conditioner.   The only problem is, at the panel there is no "spare" fuse or breaker.   So how do you think the problem was solved?   Yup!  They simply inserted the wire under a screw that already had a wire (sometimes 2) under it!   That's not solving the problem.   It's adding to the problem.

All this will overload the fuse or breaker.   When that happens, things get hot that are not meant to be hot!   Anytime anything gets hot that has electricity going through it, costs you money!   If it's your iron or toaster, you expect it to cost you money.   If it's a wire, fuse or breaker, you may not like it, but it costs you money too!

Another area along this same line, is the wiring from your electric panel to the meter.   If you are trying to draw more current than the wire is rated at, it heats up.   Guess who pays for the wasted heat.   Guess who pays for it when the wire shorts due to a constant overload!

The wiring from the meter to the weatherhead (If overhead service) if overloaded will heat up too.   The only difference, it doesn't cost you in more electricity. It heats up and could cause a fire.   It also lowers the voltage at your equipment.   Equipment is designed to function at a certain voltage.   If the voltage is not held within a certain margin, the current can be higher than normal and of course that will cost you more.   The equipment if not operated at the correct voltage will be inefficient and its life will be shortened.

For example, if you have wire that is too small, a loose connection or someplace that is producing heat, and that wire is going to a motor, the motor will probably be turning at a lower rpm, producing less power, heating the windings, shorting the life of the motor and taking longer to get the job done, using more "total" electricity, which costs you more money!

That was a long sentence, but I didn't know a better way to explain it!