[Manarus]

Lube is actually very important, if you want to enjoy the play. It makes a huge difference. Water based lube dries out relatively quickly, so I don't really like this kind of lube. What I use instead is silicone lube, or as well coconut oil and lately also olive oil (though olive oil is quite messy because it is very fluid. Coconut oil has the nice property of being relatively hard at room temperature, but gets very viscous at body temperature, making it an ideal lube. And it is also good for the skin)
As already mentioned: Don't use oil together with condoms, as it will destroy them.
For toys made out of stainless steel and silicone (and also glass, but be aware of not breaking it) you can use either silicone lube or coconut oil.
Personally, I wouldn't use toys made from any other material, such as cheap plastic toys or rubber toys, due to the chemicals inside them. Rather stick to stainless steel, or if you want it softer, to true silicon.

And be aware that not all toys sold as silicon toys actually ARE made out of silicone. (Most of them are, though). But it also happened to me that I bought a toy labeled as silicone and it was not. You can make some different kind of tests to figure out if your toy really is silicone. First, I clean my toys in boiling water. If the toy takes damage, it is clearly NOT silicone. If they survive it, I bake them in the oven at 200°C for 2 hours. (Monitor it the whole duration. If you put anything other than silicone in the oven, you could produce toxic gasses or even start a house fire. So be very careful with that. When in doubt, don't do this step.)

Why am I mentioning this? Because silicone toy sellers regularly state that a silicone toy never should be used together with a silicone lube. Based on my research, this is simply not true. Silicone is a very stable material (that is why I like to use it to insert it into my body), and all usual lubes can be used with silicone toys. It is said that this warning appeared when customers experienced some serious issues when applying silicone lube to "silicone" toys, which most probably were fake and not made out of silicone at all.
So another test, if your toy is actually made out of silicone, is to apply silicone lube to the toy, leave it there for some hours, and observe if the surface changed in any way, if it changed colour (after drying the lube off) or if it dissolved the toy. If yes, then your toy is not silicone.

So, this was quite some material education now^^