Outdoor Rooms
Divide the outdoor space into areas, each with it's own function and connect them with paths.
The idea of treating outdoor spaces as rooms that are an extension of the house is more common in warmer climates, but maybe is even more important in colder climates so that the limited good weather can be best enjoyed.
There are three ways outdoor spaces work as an extension of the house: as views to the outside which act as extensions of a room, as intermediary spaces (e.g. a porch) where you are partly inside and partly outside, and as spaces in their own right.
A porch is an old notion that has come back into fashion largely from proponents of new urbanism, because porches are the ideal space to allow for the casual meeting of neighbors. A porch should feel protected, but not enclosed, close enough to the street so as to make interaction still possible, but not so close as to make it required. To be usable, a porch needs to be at least six feet deep: enough for a person to sit and still have room for someone else to walk by. Eight feet (including railing) is very comfortable. While the location of the porch is mostly dictated by which way the house faces the street, the availability of sunlight should be considered also. West and south facing porches are hotter than north and east ones, which could make for a longer season of use, or possibly make the porch too hot in the summer. Because porches involve big overhangs, south facing porches occupy precious sun gathering space, and will tend to make the rooms behind them very dark unless other sources of daylight can be incorporated. Porches facing the prevailing winds will tend to be cooler than protected ones. In all cases, porches tend to be used in the afternoon and evening, so consider those conditions when designing your porch. Locating porches in corners allows some of the properties of both directions to be used.
Patios and decks are spaces for outdoor living that have a specific relation to the sun, although they can be partly, or even mostly covered. In cooler climates, they generally want to be in or near the sun, while in hot climates, shade or only morning sun is better. Unlike porches, patios demand more privacy. Some place should be made for hanging out in the sun, whether it be a patio, a deck or whatever. Give it enough room for a a couple of chairs or chaise lounges. An outdoor space that is "half hidden" is more desirable than one that is totally private or totally exposed, because it fulfills our need to feel protected while allowing us to feel connected to the outside world.
There are an enormous variety of outdoor spaces that can be built, and each aspect of the site lends itself to different kinds of spaces. Privacy can be created by fences, but also by evergreen shrubbery. The north side of the house will stay green much longer than the south side, while the area right next to the south wall of the house will be the warmest location. Odd, curving shaped areas add more interest and an organic feel to the outdoor spaces, and even small curves to walkways and driveways add interest. A perimeter fence keeps the dog in, but also provides a huge emotional barrier for most people. Lining your perimeter with varied landscaping provides as much or better privacy, but is more inviting.
Of all patterns, this is the one that almost universally gets ignored. Creating good outdoor spaces is not easy, and can be quite expensive, but it also turns unused space into useable space.