Readers Live Vicariously
It is always important to remember that connecting with your reader is the most important thing. To do that best, the reader should feel as if she is experiencing the story as one of the characters. Generally for the highest impact this means the action happens to the viewpoint character.
Action Happens To A Viewpoint Character
That means to have the largest impact on your reader you will have things happen to your viewpoint character and then the reader will feel as if those things have happened to her.
First, Think As A Screenplay Writer
Remember, when you watch a movie you do not know anything about the way the character feels except for the way you see him react to outward events or what he says to other characters. However, he may be saying things to other characters that aren't true. In a movie we cannot know what the character is actually thinking (except in odd cases where there is narration).
How Might An Actor Portray A Feeling?
That means you want to consider how an actor might portray a feeling.
That is probably the key to getting to better writing.
You'll need to imagine how you might see the characters actually reacting to some stimuli.
Once you "see" it, write it down in exact detail.
A Very Simplistic Example
Let's try this with a character who is searching for hidden gold in the desert.
Ralph took a deep breath and stuck his hand into the hole at the base
of the cactus. His eyes darted left and then back right as he felt
around inside the cactus. Nothing. But this was where the old man had
said it would be. Ralph shook his head in an attempt to brush the
sweat out of his eyes. Maybe further inside. He pushed with his legs
and now his entire arm was inside the cactus. Stabbing pain pierced
his index finger and he jerked his hand out of the cactus and pulled
it toward his body and screamed. He looked down at his hand and a
wave of nausea rippled through him. Must stay conscious. Have to get
Show As Much As Possible, Then Allow For Reflection
Show as much as you can as physical actions. Then, show the character reacting to those actions and it'll help create the strong feelings in your reader because they'll experience the physicality of your writing along with the emotion, because it'll feel much more realistic and immediate as if it is happening to the reader herself.