When planning for trees and bushes, imagine them at full size.  This way you can determine your spacing better.

When designing your sprinkler system make sure you zone area appropriate.  

Dont mix bed zones with grass zones.

Drip zones should always have there own valve.

Never mix shade areas with full sun areas.

If you increase your watering to help poor performing plants but problems still persist.  Check your soil before your next watering.  You will be surprised, most people over water there plants.  Over watering looks a lot like under watering.  In most cases if you let your soil dry out a bit more in between waterings your plants health will improve.  

Starting up your system?  Please remeber to close all hose bibs, drain valves and anything else you opened up to let things drain or to allow for freeze expansion.  Flooded basements are no fun.  

On secondary systems when your done drainig your system, close the main valve at the street.  This way in the spring when it comes on and you're at work it doesn't run all day.

When doing your final grade, determine if you like your grass to be blocked next to the sidewalk or flush with the sidewalk first.  This way you can grade to the actual depth you need to get the final result you want.  Don't leave it up to chance you will be dissapointed later.  

Chasing brown spots around the lawn with the hose.  If your head spacing is right then proper nozzling will do wonders.

When planting, make sure you dig the right size holes, mix in the right amount of amendments and plant to the proper depths to ensure your plants and trees have the best chance to flourish instead of sit stagnant for several seasons.

Lighting can add a whole new demension to your landscape.  Nightscaping will take your yard to a new level.  Its almost like having two yards in one!

Notice the dirt sinking around the foundations of the houses in the neighborhood.  Thats from poor compaction around the house.  Water settle the dirt around the house for several days to accelerate the poor compaction before you install your landscape.  You will save yourself a lot of heartache.