It's not real critical. When wiring phone centers we used metal raceways (or a thrown-together wood one) in the ceiling, but for my house I used pipe clamps like the one you posted at about 4' spacing. I like to add a wrap of double-sided velcro around bundles going to the same box, also about every 4'. Near the demarcation point I might use a few screw-in hooks like those used to hang bicycles if there are a lot of cables going out in one direction.

Don't fasten the cables to anything too securely. That way you can use the old cables to pull a new one if it becomes necessary.

One important detail: do not use zip ties. They can constrict over time and damage the cables they're wrapped around. (They're also tougher to pull new cables through than velcro loops.)

You didn't ask about routing them, but I guess it's relevant to explain the assumptions my recommendations are based on. I always do horizontal runs in the floor/ceiling and then run vertically within the bay where the junction box is located. (Rather than meandering through the wall as shown in one of pumpkin's photos.) This means less holes to drill and usually less resistance when pulling the cables. I also leave an empty bay (two studs) between mains and network cables, so I don't need to worry about securing the drops (recommended distance is at least 1' apart when running parallel to mains).

If you wanted to make pulling new cables even easier without doing a full PVC conduit setup, you can just install PVC fittings such as 90° elbows where the cables pass through the top plate or sole plate. That's were all the friction is going to come from when pulling, so some nice smooth PVC lining the holes can smooth things out nicely. (This of course assumes you'll use one of the existing cables to pull the new ones. Obviously you won't be able to run a fish tape without the sections of PVC connecting the fittings.) The fittings would also ensure that you don't go under the cable's minimum bend radius of 1 inch.

One other thing that I'll mention just in case is heat. Large, tightly-wrapped bundles of cable (think 50+ cables) that are being heavily utilized have the potential to trap heat in the center which can eventually degrade the insulation and cause shorts. Unless you're running a grid computing cluster at your house that's not likely to be a problem though. A more likely scenario for the average home owner is the use of Power over Ethernet, which will generate more heat. If you're planning to use PoE I'd limit bundles to 7 or 8 cables, just for good measure, even though I think the odds of a problem are still very low.

You'll have to check with the Authority Having Jurisdiction, but I'd say "smurf tube" on a wall in a shop is a no no.

National Electrical code allows ENT for exposed work, but not where subject to physical damage. Which means if you're trying to protect your cable from physical damage, you can't use ENT (unless you protect the ENT from physical damage as well).

National Electrical Code 2014

Chapter 3 Wiring Methods and Materials

Article 362 Electrical Nonmetallic Tubing: Type ENT

II. Installation

362.10 Uses Permitted.

1) In any building not exceeding three floors above grade as follows:

a. For exposed work, where not prohibited by 362.12
b. Concealed within walls, floors, and ceilings

362.12 Uses Not Permitted. ENT shall not be used in the following:

(9) Where subject to physical damage.

If you don't want to use metal conduit, schedule 80 PVC conduit is identified for areas of physical damage.

Article 352 Rigid Polyvinyl Chloride Conduit: Type PVC

II. Installation

352.10 Uses Permitted.

(F) Exposed. PVC conduit shall be permitted for exposed work. PVC conduit used exposed in areas of physical damage shall be identified for the use.

Informational Note: PVC Conduit, Type Schedule 80, is identified for areas of physical damage.