IMHO Â..I would take into consideration air flow, and where low lying frost pockets are. Also how drip irrigation would be layed out (if being used). Plant in order of pollination to get the best possible pollator nearby. Leaving enough separation so a tractor can get through, and to decrease pest or disease spread. Staggering harvest may also be helpful to you.

You could find info on some of this, on the net.

layout
http://www.wvu.edu/~agexten/hortcult/fruits/om100.pdf
http://www.pwarb.com/garden-orchard-design.htm

Some space saving ideas
http://www.orchardchronicles.com/2009/02/the-high-density-home-orchard-hdho/

layout
http://www.taranakifarm.com/blog/?cat=12

http://ohioline.osu.edu/hyg-fact/1000/1401.html

bagging principals
http://www.homeorchardsociety.org/article/6/

helpful book

http://anrcatalog.ucdavis.edu/GrowingVegetablesFruitsNuts/3485.aspx

Raspberries basics
http://www.backyardgardener.com/plants/graspberry.html

Blueberry needs
http://www.canr.msu.edu/vanburen/e-2066.htm

Sounds like fun!

You speak of design as though you are intent upon some sort of visual or artistic goals rather than mere production of maximum fruit with minimum effort.

I personally am a big fan of larger sized trees for small orchards as they are longer lived and more tolerant of inexperience or occasional neglect.

I'll refrain from specific recommendations since anything I suggest will be much more cold-hardy than you need and may not do well in warm weather.

I highly recommend an old book (1981) by Gene Logsdon, "Organic Orcharding," which has a very useful discussion of setting up home orchards, giving plans for orchards of different sizes (1/4 acre lot, 1 acre, etc.).

I prefer enough room between the trees for tractor access. I like to run the tiller between the trees for weed control. I also use the space for growing pumpkins or corn or...

Zeuspaul