Tense

    I was told by many people to keep my tense consistent through out the whole essay; sometimes thats hard to do. I couldnt avoid shifting from past to present or present to past. Sometimes without the shifting the sentence wouldnt sound right at all. I just want to ask everybody some ways to avoid tense shifting. I was told by somebody that using the perfect tense might help but the person elaborate so anybody knows what he was talking about that will be great. thanks

Just about any tense offers the same problems to the careless writer.  Remember that you are telling a story (He went to the store and bought a sandwich; then he sat on the beach and ate it) or giving an opinion (Oysters are tricky to open, but they sometimes have pearls within, and their shells can be used for garden paths) or describing a process (First fold the paper in quarters, then cut off the corners with scissors and place the folded remnants on your nose).

It will take review and revision to ensure that your verb tense remains consistent.  Of course, sometimes you do need to shift tenses (Every day I grab the same bag that I bought in St. Louis in 1976)-- but if your critics are complaining about your inconsistency of verb tense, then pay attention to my earlier advice.