Would like to add a few trees - a trio of dogwoods 2 pink,
one white - different varities & sizes. In addtion, a star
magnolia & maybe a real edible cherry ---...

The garden centers have a nice selection, from $100 to $250
are the starting sizes.

So -- dig a hole and plant according to instructions right?

Easy enough for a basic homeowner (re-done lots of inside fully
self - kitchen, bath, drywall, basic plumbing - automotive engine
transplants etc....

Or - should I go with a pro? With a warranty etc. etc. (Something like
Meadows Farms, BlueMount, - I've gotten a few "designs" for $, but have
been totally underwhelmed by "design").

If the planting goes well, I can save some good dollar to put towards
more/bettter vegitation - and risk some loss. (I figure I can do it twice
for the cost of once with a pro install ...

I'm ready to start tomorrow!

For larger trees, I'll cut out a section of lawn, often a circle (say 6' across for a 4'ft specimen. Edge the area and cover the remaining turf with a inch or so of newspaper --- that'll kill the grass and weeds. Cover the newspaper thoroughly with mulch. You won't have to weed around the tree for a year or so, and you'll avoid getting too close with a string trimmer, mower or tractor.

Working a slow release fertilizer into the hole such as Plantone always makes me feel better.

Depending on the size and sturdiness of the trees you may have to so staking or tie backs... probably not based on your planting list which sounds great.

Do shop those prices online and at your local Home Depot or Lowes. You should be able to find good size specimens for no more than $75 each.

Drench thoroughly after planting, drown it.
Drench thoroughly the following day.
Water approximately weekly or less depending on conditions.

The difference in the emotional attachment you'll have with a tree you planted vs. a tree that was planted for you is quite worth the effort.

So, in the fall I picked out three bigger trees with a landscape designer, and they were put in in mid October 09.

Late March - not good (about 5 months):

Crepe Myrtle - growing nicely its first spring.
Forest Pansy Redbud - dead. Not a bloom or bud.
Yoshino cherry - 1/2 dead, full credit for dead.

I got credit for the two - $500 with an original cost of
$740 - So I'm out $240 (plus some tax, mulch, and
stuff they planted the trees with) ...

The difference is in the warranty - 1/3 is not counted
as it is "labor".

I can get $500 worth of trees as credit at
Meadows Farms.

So - I have to risk 66% more dead trees on arrival,
and more potential loss.

But hey, I do get two new dead trees, and I get to
remove them myself for $240!!

Serious disappointment. Yes the warranty stated that,
but how can you go wrong hiring the big pro company?

Result? DIY. Buy a lot of small trees, from not the
big places.

One thing to watch is the depth at which you plant. Be sure you are an inch or so above grade with the new rootball. Also, the recommendation these days is to backfill with the native soil . Otherwise the roots will not spread as they should (they'll stay where the enriched soil is. If you are amending the whole yard, no worries. Even some landscaping folks plant too deep. Make sure you can see the root flare at the base of the trunk.