SM57 sounding too harsh.

[Bubba po]

Get a flashlight to shine through the grill cloth to see the speaker.

Once you find the perfect placement, take some strips of tape and use them to mark the place on the grill cloth to point the mic.

Simple as that, eh?

 

[Farview]

Usually... most grill cloth is see through to some extent, you just have to light up the speaker to see.

 

[Greg_L]

Simple as that, eh?

Yeah it really is. I use a tiny little LED flashlight. Modern Marshall grill cloth is pretty easy to peek through. The old weave is a little harder to deal with.

 

[Greg_L]

No big deal!

 

[JDOD]

My grill cloth is really dense. It's annoying when placing a mic!

 

[Bubba po]

It's always good to learn a new trick. Thanks, men.

 

[miroslav]

My grill cloth is really dense. It's annoying when placing a mic!

I've got one amp (TopHat Club Royale) that has grill cloth that is made of thick salt-n-pepper cotton thread...and the weave is tight, so with that one, it's hard to see the speaker....the flashlight has to be a real bright one to cut through.
Otherwise all the others are pretty easy to see through with a flashlight.
I keep one of those compact LED flashlights right next to the cabs just for that purpose.

Some people like to mark the grill with tape...but I just use the flashlight as needed. The tape is good if you're recording across a few days, and you have to take the mics down...that way you can hit the exact same spot every time.