Changing Tick Mark Style

Probably the easiest way of altering the tick marks for a large number of graphs
is to create a function which will change the tick marks as desired.

Function Components

First, you will want to generate the graph information, but not plot the graph. This allows you to
generate the current plot's tick marks for use later in the procedure. To accomplish this you
can set the display function to Identity, which will disable the display of the graph. Example:

preplot = 
        Plot[(x^2), {x, 0, 10}, 
          DisplayFunction -> Identity];

Next, we will want to get the tick marks from the generated graph information. To do this we use
the following:

oldTicks = AbsoluteOptions[preplot, 
            Ticks][[1]];

Using this information and replacement rules, we can then easily alter the way that the tick marks
will be displayed. The following will change the size of the major and minor tick marks, then the
thickness of these marks, followed by altering the color that all of the tick marks are displayed in.
These rules can easily be altered to make the replacement more general or to better suit your needs.

newTicks = 
        oldTicks /. {({0.00625, 0. }) -> ({0.0125, 
                  0.0125}), ({0.00375, 0. }) -> ({0.0075, 
                  0.0075}), (AbsoluteThickness[
                  0.25]) -> (AbsoluteThickness[
                  1.5]), (AbsoluteThickness[
                  0.125]) -> (AbsoluteThickness[1]), (GrayLevel[
                  0. ]) -> (RGBColor[0.9, 0.4, 
                  0.9])};

Finally, we plot the final graph with the new tick marks, using Evaluate in order to access the
information stored within the variable newTicks.

finalplot = Plot[(x^2), {x, 0, 10}, Evaluate[newTicks]];

Putting this all together

We can then put all of this into a function by using Module. One thing to note in the following
definition is that the input opts has three underscores following it, this allows us to pass a series
of Plot options, such as AspectRatio,  along to the function. However, if you plan on using
Frame->True you will need to modify this function to use FrameTicks or you will not see any
change in the plot.

myPlot[f_, overrange_, 
        opts___] :=  
Module[{preplot, oldTicks,  
          newTicks, finalplot}, 
        preplot = 
          Plot[Evaluate[f], Evaluate[overrange], opts, 
            DisplayFunction -> 
              Identity]; 
oldTicks = AbsoluteOptions[
              preplot, 
              Ticks][[1]]; 
newTicks = 
          oldTicks /. {({0.00625, 0. }) -> ({0.0125, 
                    0.0125}), ({0.00375, 0. }) -> ({0.0075, 
                    0.0075}), (AbsoluteThickness[
                    0.25]) -> (AbsoluteThickness[
                    1.5]), (AbsoluteThickness[
                    0.125]) -> (AbsoluteThickness[
                    1]), (GrayLevel[0. ]) -> (RGBColor[0.9, 0.4, 
                    0.9])}; 
finalplot = 
          Plot[Evaluate[f], Evaluate[overrange], opts, 
            Evaluate[newTicks]]]

This example shows the input of Plot options to the myPlot Function:

myPlot[(x^2) + 4 Sin[x] - 2 Cos[x]^2, {x, -10, 10}, 
        AspectRatio -> 1, 
        Epilog -> {Text["text", {2, 20}, {0, 0}, {1, 
                0}]}];