i prepared gift already vs i have prepared gift already

Some examples from the web:

• And there are already enough gifts already.
• And I prepared a pink layette.
• I prepared a very unromantic evening.
• I prepared the guesthouse for you.
• I prepared your canoe with cedar boughs.
• I prepared lavish banquets often Leopold Leopoldovic.
• It's just one course... which I prepared personally.
• And I prepared for my bull.
• A lie! I prepared the glasses.
• I... I prepared some tea.
• I prepared the entire plan myself.
• And... I prepared this for your approval.
• I prepared her here for burial myself.
• Not like I prepared an interpretive dance or anything.
• No, I prepared everything for you.
• I prepared a soup with herbs from the garden.
• I prepared a report on how to improve the situation on the island.
• I should have been clearer when I prepared you for this meeting.
• As rapporteur, I prepared a draft version which already exceeded the set length.
• I prepared a statement for you to sign to that effect.

Some examples from the web:

• That is why I have prepared a surprise...
• I have prepared a nice place for you near here.
• I have prepared a kid who looks like him.
• I have prepared severance package that is more than... equitable.
• Frank, I... I have prepared an incredible plan b.
• With your permission, I have prepared a few words.
• I have prepared a nostalgic meal... I.E., not healthy.
• I have prepared a list of my top-10 choices.
• Today I have prepared something else.
• I have prepared two months' supply.
• To celebrate a great victory I have prepared a special event.
• I have prepared a pass for you to sign.
• Come, I have prepared a little dish...
• I do not care, I have prepared a surprise.
• I have prepared a magnificent show.
• I have prepared a solution of laudanum, a paregoric.
• I have prepared this report twice.
• Sergeant Perez and I have prepared meals using traditional Army ingredients.
• And I have prepared meat and potatoes.
• The class I have prepared today -