What sort of squashes, and what for? They generally have lots of flowers and potantially lots of fruits. If you want large or show ones( I am growing a couple of "atlantic giant" pumpkins for Halloween which I just want big) I suggest you remove all but one. If you want courgettes, remove before they get too big and then the plant will try to produce more. Cucumbers (are they still squashes?) need male flowers removed or they taste horrible.
Hope this helps some, but more info would be useful.

it varies depending on the variety and how many you want per pant. lots of fruits mean saller fruits. only one make it a big fruit. if they are for eating then I'd go for 3 or 4 max.

If you mean butternut squash the number of fruits is often determined by how you train the leaders and how many flowers get pollinated.

I would say a fair average is around half a dozen.

Thankyou all for the responses. Teegee it is indeed a butternut squash so that was very helpful.

I grew butternut In the gh and only allowed 2 per plant because of the space......never having grown them before I tookthe first off when the green had gone....too early!. I left the others for much longer and they were much better