if your going sheet to sheet from vba and it's the flickering of the sheet
changes.. then you can use:

application.screenupdating = false

then when done set it to true.. and you won't see the flickering.

when you want to get rid of the flashing screens, put in the next line at the
start of the macro:

Application.ScreenUpdating = False

and at the end:

Application.ScreenUpdating = True

This will freeze the screen and run the whole process at the background, without
updating its screen. Your macro will run faster as well.

Don't use copy/paste/select/activate etc.

Access them properly from the code ...

Worksheets("101").Range("H8").Value
Worksheets("101").Cells(27, 6).Value

or whatever.

Alternatively, turn screen updating off (it's an Application property).

The use of range names and the Offset method can make it easier to refer to data
on other sheets programmatically:

ActiveWorkbook.Sheets("Widgets").Range("SalesData").Offset(1, 0).Value

Also, you can use the Vlookup function from VBA:

Data$ = Application.WorksheetFunction.VLookup("WhatToLookFor",
ThisWorkbook.Sheets("Widgets").Columns("A:D"), 2, False)