I have something akin to an answer, but I might consider it more like advice.

1. Rust begets Rust- purely anecdotal, but I feel like rust left unattended promotes more rust. I would first work to rid yourself of as much rust as possible. Things like naval jelly, baking soda and similar will be your friends.

2. Moisture is the enemy - Whether it be your home, your tools, your electronics or otherwise, moisture tends to be an issue. If you haven't already, I would invest in a relatively inexpensive dehumidifier. I keep my basement around 35% humidity and love it.

3. Oil - The only thing I know if that consistently prevents rust of iron containing items is oil. Wax is ok, and can be effective, but nothing beats a very fine mist of mineral oil (or really just about any oil that won't go sour, and a cotton rag. I find mineral oil has the least effect on the tools and the wood they cut. It takes a microscopic thin layer to prevent that oxygen from getting to your tools.

Silica gel packets won't work well if your tools are on shelving. They'll just dry out the surrounding air, which will be replaced by other moist air.

But, if your tools are in boxes, silica gel packets will be fairly effective. Naturally, the larger packets are more effective than the smaller ones.

I've always had good results with them.

Camelia oil.

It is very affordable (around 15€ per liter), it doesn't stain, nor gum (nor smell, nor taste). It's not aggressive to the skin or otherwise hazardous to your health (in fact you could drink it, and you could use it as lotion and for your hair, indeed many high-quality body oils contain camelia).

Apply a few drops with a dispenser and spread it evenly so the entire surface is covered, then wrap your tool in an old rag before boxing it (or, preferrably a leather sheet).

You can remove the oil prior to using the tool with one swipe of a paper towel.

WD40 is much better (I find) when not applied with an aerosol; get it by the litre and brush it on with a rag. That's my usual method, and it works fine (except when I forget). I do it every single time I'm going to not use a tool for more than a couple of hours. The smell is far less than when spraying the stuff.

With wax, if you want to avoid having to warm it, you can (sort of) disolve it in some metho and brush it on with a rag.

Of course, the traditional system is a mutton roll! A strip of fabric, with animal fat laid crossways on it, then rolled up. Tie it up with string, cut one end off neatly, and use that end to smear grease all over your tools after use. Lasts ages!

I agree with the all the suggestions to use oil. I glued a piece of carpet on a board next to my bench. Whenever I am finished with a tool - I squirt oil on the carpet and rub the tool against it. This is easy and saves oil.

If you already have rust - I have found that the "SandFlex Flexible Abrasive Block, Fine Grit" - is excellent at cleaning up tools. Also, "Evapo-Rust" is unbelievable effective, albeit expensive way to clean up rust. It is safe on tools.

For longer term storage you can buy "Uniwrap rust-inhibiting paper".

In general the best way to reduce rust is to reduce moisture. I highly recommend running a dehumidifier in your shop.

Get the tools rust free by polishing with steel wool or scotch brite, wipe clean with oily rag-- leaving a very fine oily film, then apply a soft wax-- I have had good success with Johnson paste wax. If you can't ensure a low moisture environment, the wax film will do as anything else to prevent reformation of rust but leave the tool useable. If the storage is for years and the tool will not be used, try Cosmoline

Teflon chain oil from Dupont provides a nice tough static and rust free film.

It is used for motorcycle chains and has been time tested for not collecting dirt, rust and dust. Have to let it dry on the first application. Just need a small amount too. A bit pungent so spray in well ventilated place. Great for all kinds of metal in humid situations.

CRC food grade Silicone Lubricant is magic on any metal, Never leaves a mark and does not go away unless you want it to, They use this stuff in museums when long term storage with protection is of the utmost importance, Oil just dissipates eventually, I moved to this Lubricant and will never go back to oil for protection, I use it on knives, Swords, door locks, antique straight razors ect ect ect, Its says food grade but I wouldn't eat it, unless of course you want to live forever!!...:)

I use Silicone lubricant, not WD-40. This is mostly for my table tops and such. March/April I go through my shop and use Silicone on all my metal topped machines (table saw, joiner etc) to keep them from rusting in as the moisture content in the air rises and the tops are still cold condensing the water and causing rust. One good thing about Silicone is that it doesn't leave an oily residue, especially not on wood when you use the tool later.

One of the odder suggestions I've seen: mothballs in the drawers. Mothballs work largely by outgassing, and since the vapor is heavier than air you should, theoretically, wind up with a layer of vapor pushing air -- and oxygen -- out of the way.

On the other hand, that's fairly nasty stuff, especially if your workshop is poorly ventilated.

Just tossing it out as an observation, not a recommendation.

Look at what firearms collectors do to protect guns from rust. They are fanatical about rust prevention. And they have developed a series of countermeasures to protect their gun metal (which is often installed in very high grade wood stocks):

1. First, immediately after use always apply a light protective coating to steel. WD-40 does not cut it. There are a wide array of higher-tech protective lubricants for firearms, and any will be fine for tool steel. These range from oils to silicones, and from sprays to wipes. (Update: Per comments, it sounds like silicone-based coatings should be avoided because undetectable amounts that get on wood can interfere with subsequent finishes!)

2. For long-term storage supplement the lubricant with a rust inhibitor. These are available as sprays for direct application, or impregnated paper or cloth to add to storage containers where there is not much airflow. (They are volatile, so if the tool is stored in the open these will eventually evaporate.)

3. Keep relative humidity low – never above 40%. One way to do this is to store your tools in a room with a dehumidifier. Another is to dehumidify the storage container. There are desiccant systems designed for gun safes with built-in capacity indicators and plug-in rechargers.

4. Avoid condensing conditions. This would be where the temperature in the storage area is allowed to vary widely: When air temperature increases significantly, then the relatively cold metal will attract condensation before it warms up. One way to avoid this is to keep the tools in a heated container. For example, it is common to leave a 20W light or other device on at the bottom of a gun safe. (Safes usually aren't airtight, but this ensures that the contents of the safe will always be a little warmer than the surrounding air.)

the first step in rust prevention is keeping tools clean. As clean as possible, at the very least preventing dust/wood particles from accumulating. Wood retains moisture, and moisture close to metal will eventually work its way through all organic coatings. It's for this reason that I keep all my handtools in a cabinet.