Order an amp cutter online and just draw with a normal needle. Just make sure you have the opening of the sharp end of the needle facing down to ensure you get as much of the product as possible.
No need to use a filter, but i know guys who do. I've been using amps for years and never had a problem. Using a pen cap is also a great idea, but sometimes it will shatter the entire amp unless you score it first with a file, so using a cutter is the best option.