Why do my Layer Styles Look Terrible Sometimes?

It's hard to explain how it looks

If it’s hard to explain how it looks please post an example, a screenshot, … with the camera-icon button.

It hard to tell what you are doing for  you provided little information. No setting, effects, sizes. examples. 

Canned layer styles in the layer style palette are created for a particular document with a particular resolution and look  best on documents that have that resolution.  Layer style effect settings are stored in absolute pixel values.  They are  not relative to a document resolution.  That is why there are special options in Photoshop for scaling layer styles,  You well see an option for scaling layer styles in the Image size dialog in CC this is hidden but can be exposed using the CC image size dialogs setting icon.  Also in Photoshop menu Layer you will see Layer>Layer Style>Scale effects... .  Often layer styles need to be scaled to look good. Almost always when you change a documents DPI resolution.  Changing Image size and maintaining the same resolution should work well not need scaling there will be more or fewer pixels that get the style effect  the resolution  scale was not changed.

A style save for a small web image the has  a 72DPI setting image will not look good if addted to a large 300dpi image becayse the diffence in DPI.  Styles are applied using absolute number of pixels.   If a style added a stroke 100 pixels wide on the 72DPI Image that stroke would be would be 1.388" wide the same 100 pixel stroke on a 300 dip image would be 0.333" wide.

Screenshots make the world go round as Mr. Pfaffenbichler already requested. Just assuming that someoen must have already faced the same issue usually goes nowhere. the closest I can think of are color profile issues where the Adobe color engine may not pick up the current monitor profile correctly, but your info is realyl too vague and generic to make any specific assumptions.

Mylenium

Resolution can have a lot to do with how layer styles look.  It also depend when layer styles get added and how the style is added. Preset layer styles are created on some document with some dpi resolution Photoshop seem to store that information and also the the layer style effect pixels settings in the preset. When you use these presets Photoshop seems to scale the preset layer style to the current document resolution.  If you use named layer style presets in actions the layer style will be scaled to the preset for current document resolution size.  If you record adding a layer style using the  layer style dialog there will be no scaling done by Photoshop the layer style will look different on different resolution documents.  I just recorded an action that creates a new 5"x5" 100DPI document and add two 1"x1" gray layers then layer styles are added to these one a preset the other layer style is recorded into the action.   I added a stop before the layer styles are added to be able to change the document resolution before the layer style are added.  The followings screen capture shows the result of two plays of the action and the action. The document on the left is a 100DPI document for no resolution change was made, the document on the right is a 300 DPI document image size was used to resample the 100DPI document to a 300dpi document before the styles are added.  The red stroke style is a preset and you can see the it was scaled.  The blue stroke style is a 20pixel stroke recorded into the actions using the layer style dialog.  It did not get scaled its 20px wide in both documents, The documents look the same except for the blue stroke style.  The left document viewed to fit is a 175% zoom where the right document zoom is 58.2%.

I created the stroke20RedInside preset on a 100dpi document setting the stroke to be 20px.  Use on a 100 dpi document the stroke is 20PX wide on a 300Dpi document the stroke becomes  60PX wide. In the Layer style dialog all you can set is a number of px you can not use a relative unit like inches which is relative to DPI. So if you use the layer style dialog to record adding layer style the effect in an action the action step will always used will always be the px value recorded. There is no other document resolution involved soe no scalling is done.  Presets seem to have an advantage here for the document use to save the new preset resolution seems to be recorded  into the preset and Photoshop uses that information  to scale the effects settings  to the dpi scale of the document the style is being applied to.

So the is a big difference between apply layer style and set layer style recording actions.

Have never seen that happen.  When it happens the next time see if resetting all Photoshop tools  clears up the problem. If that does not see if resetting your user id Photoshop's preferences clears up the problem.  When Photoshop messes up on me the first thing I do is check the current settings. Then reset tools and then reset preferences usually one of these things clears up the problem I'm having. I have seen Photoshop do some strange thing when a preference file becomes corrupt.  Photoshop preferences files becoming corrupt has been happening for as long as I can remember.  Adobe even added a start up feature triggered by a shortcut key combination to have Photoshop  delete your Photoshop Preferences files and then generate then generate new default set of preference files before Photoshop initializes itself.

Were the screenshots both taken at View > 100%?

What are the settings?

Were both images identical in resolution and pixel dimensions?

The texts in the screenshots are slightly different, so something may not be identical after all.

The Layer Style is causing Type Layers to assume different heights (ignoring Glow, Shadow etc.)?

Could you provide the two files?

To me it looks a lot like layer style scaling. I have never see layer style scaling produce the jaggies like in the top left example.  Play around with the slider in the pop up dialog from menu Layer>Layer Style>Scale effects... I would also like to have a copy of the layer style  and files involved. The top left example also has the look of something the has been resized up in size  that was done via interpolation not vector graphics.  So it may be a raster layer not a text layer.