How do you use a darning mushroom?

I've inherited some of these, but they just don't seem to make my (mending) life easier


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I usually put my left hand inside what I'm working on and use my needle in my right. I feel silly asking, but how do you hold it? How do you get the needle through when there is a wooden surface behind the material?

You'd hold it in your left hand inside the garment and push the needle into the wood instead of the skin of your left hand. It deflects off the surface instead of going into the wood and then you tip the front of the needle up and back out through the fabric you're repairing. (I use a little glass bowl instead of one of those, but I think it's essentially the same.) (I'm also usually patching and not darning.)

I might be misunderstanding the nature of your inquiry but hopefully my answer will help you clarify if that's the case.

Christopher Weeks wrote:It deflects off the surface instead of going into the wood

I think this is the thing I'm probably struggling with. Maybe I'm getting the angle wrong, but getting the needle to come out again where I want it is also tricky.

If you're keeping the curved surface mashed up tightly into the fabric, maybe try relaxing that a bit. You can "receive" the needle as it pierces 'down' into the garment, then back the mushroom out so that you have free movement to control the needle as you tip it up and back out. You don't need to fight the mushroom for access. And I'm not talking about big changes -- but letting it go slack by backing it out 1/4" gives you control of the needle and the ability to fold or otherwise deform the fabric for your outward thrust. I'll be interested to see what a more advanced sewer has to say about this.

We used these to darn socks mostly, so the mushroom was popped inside the sock then the non-dominant hand held the stalk of the mushroom and sock together on the outside, then the dominant hand performed the darn on the top - first the threads parallel top to bottom then the fill-in threads  across them, weaving in and out. The trick is to get the initial threads close enough that the weave will fill in completely.   Works on larger items, but tend to be a bit more cumbersome for the 'holding together' hand.  Not an invisble darn, but extends the life of the item.
Edit to say:  Just read back a bit - the needle is inserted sort of parallel to the mushroom top, rather than stabbing into the fabric and glides across the top of the mushroom... those in the image a really beautiful!
Edit to add  

Jill, Christopher - that helps a lot! Thank you both. I think I am both holding the fabric too tight and stabbing into the mushroom, rather than almost gliding across it.
I will have another go and see how I get on!