People are barely 100 years, trees multiples thereof. So what effect your work will have (much) later you do not know exactly. And the fruits of your labors are often for (grand) children. When growing hardwoods like oak for shipbuilding, tree, information and knowledge were passed from generation to generation.

BoomplantenOf fruit trees you may harvest earlier, after a few years. In life time we are talking about decades. For tall trees. Half standard and low strain stay shorter productive.
All plant information applies equally well to shrubs. But therefore it is often easier to divide a shrub yourself, or make graftings.

Since they are long standing, and continue to grow bigger every year you should consider well in advance where and what you want and can plant. And what is allowed by law. Generally a shrub or hedge may be up to 0.5 m of a dividing line (or on it, with the consent of both). For trees you need to stay 2m of the dividing. Check with your local authority.

Consider light about windows, sun terrace or pasture, greenhouse and under growth.
Tall trees need a lot of space and picking is difficult. You need to have a long and so a heavy ladder. You cannot hang bird nets over them. But you can attach a hammock to them. Or a swing. And you can walk underneath. And cattle can (almost) not nibble on leaves and fruit. I have heard repeatedly claim that standard fruit is tastier. But of course ‘good taste’ is subjective.
If you have little space, you can opt for half-standard or low strain.

Fruit trees you plant when they are at rest and leafless between (September -) November and March (April).
You can buy them in a nursery pot, with root ball (with a net around it) or bare root.
In that order, they are better protected to transplant, but also more expensive. Soil is heavy (and therefore expensive) to trade. Much less earth is at the roots, the more (little) roots will be broken, and so much more very fine hair roots will be dried out and dead. For smaller trees (e.g. 90 cm) this is less important than in larger (e.g. 3 m).

If you're going to get a tree then protect it good. The strain from injury of lashing and sanding, with paper (or other soft insulation), and the roots against sun, drying and cooling. If it’s outside 0°C and you’re driving at 80 km / h, then you cause a cold of - 20°C. Not exactly a temperature where you want to sit, wrapped in a plastic garbage bag. Half an hour on a trailer. Your investment would earn a better start?

If you cannot plant immediately, temporarily put the roots in loose, moist soil and give protection against freezing and dehydration.

Planting you do when the weather conditions are favorable: no daytime persistent freezing, or when the land it is (still) frozen or if it is too wet.

Given the tree (except for potted plants) lost roots, may also be branches be cut proportional. Maintain a central (heart) branch, and (one or two circles of) three or four good distributed standing branches. Shorten those quit a part. He then will also catch less wind and not be overturned. Let the last eye point outward. Before he is planted you still have easily access (from the soil).

Moisten before planting the roots well, dip them in a bowl of water.

Dig a large hole. Keep different soil layers separately, and bring it back into the correct order, enriched with old, matured compost, between the roots.
Make sure that all the roots easily fit into the hole. Do not let them stab up along the edge! Cut off damaged roots, so the chances of infestation and infection is minimized.
Toss the bottom of the hole too loose, and sprinkle old compost. Do not use fresh compost or manure that goes moldy and rot, and can damage the roots or digest them.
Bring the stem at the right level, as he was before. You can see the discoloration. The trunk itself is not in the ground. If the roots are too deep, too little air comes in, and more (chances) root suckers (shoots that grow directly from the roots) will occur.

Put between the roots a support pole. Now you can position them without damaging the roots. Put the stake on the windward side (south west), up to 10 cm below the crown, so that the strain is blown away of it and does not scour. You can also place two or three poles. Use a smooth fixation, a strip of 8- shape, with one eye around the pole, and the other around the trunk. Let pole and straps not eternal, because they are going to become fixed in the trunk. Check annually.

Crumble earth and compost between the roots, and press that without damaging the roots. Give plenty of water several times so that the soil washes in all holes and has close contact with the roots. Put finally the top layer back.

If there are grazers or rabbits then protect the bark (e.g. with chicken wire) from the ground up to nibbling height. Also check that protection on ingrown annually.
Place bark protection dependent on the grazers on an adequate distance from the trunk, because over time they are smart enough to use the fence as a stepping stone to gnaw above to the stem.

With larger animals protect the bark also against abrasion and pushing over the trunk.

With many branches and heavy fruits you better can support with struts to avoid breaking. (Or thinning fruit.)

Old trees are not replanted

Although we now have means to still do that successfully. The problem is that the root ball is often unmanageably large, and that you will need cranes and trucks. But it can be done. Also provided the necessary preparatory work.

Determine how large the root ball will be. Make no mistake, a tree with a root ball of e.g. 60 cm is awfully heavy. You cannot move him on your own. Suppose we take a tree of about 7 year, with a clod of 70 cm.
Dig a deep trench around the trunk, so you get a disc of 50 to 70 cm. All roots are cut. Try also to cut as much roots as possible at a depth of 50 cm in the direction of the stem.
Fill the trench with compost and sand, loose material. The tree can now form new rootlets. Which are necessary for proper regrowth at the new location. Let the channel not dry out.

Next year, dig off the earth around the old trench. Dig and pry loose the tree, while retaining as many roots. Just below the stem are probably the thickest and strongest roots.
Also prune the crown heavily in proportion.
Grab the root ball, wrap him, so that the earth does not break of the roots (and therefore breaks roots). If it possible with airy fabric that (in part) can stay around.
And then try to fix the tree with root ball into the new hole.