JoyAnn, sorry I didn't get back to your response sooner. I'm on vacation, and just stopped by for a quick look, and here's your response!
I know what you mean about getting into the moment and losing track of your tense. It's an easy mistake to make--and an important skill to master.
In your examples, you definitely put one in past tense and one in present tense. I'd encourage you to watch out for sentence fragments and spelling, to combine sentences in a more complex way, and to think about word choices...I've written a corrected version of the first one in red. Care to take a crack at the second one yourself?
JoyAnn wrote:I went to the refrigerator and pulled out the juice. I took a cup from the cubert and started to pour. Filled it to the top and placed it back into the refrigerator.
I stared at the inside of the refrigerator and finally pulled out the guava juice. Taking a small cup from the cupboard, I emptied the container. After the last drops dribbled out, I shrugged and returned the carton to the refrigerator.
I go over to the refrigerator and pull the juice out. Taking a cup from the cubert a began to pour. Filling it to the top and place it back into the refrigerator.
I think it's easier to use past tense but I know slip into pretense a lot because focus what I am writing and what's happening in the story at the moment, I forget about the long run and that it should be kept in past tense.