Many new Henna artists find it easier to start out using an applicator bottle. Unfortunately, a lot of people quickly learn that extended use of bottles can cause hand cramps and have multiple clogs in the tips. That being said, plenty of professional henna artists swear by them and use them without issue.
If you are having issues with your bottles here are a few hints to make it easier. Soak the bottle tips in warm soapy water and clear the end with a small wire (like a paper clip). When not in use, store the bottle with a wire or pin in the tip to avoid paste drying in there. To keep your hands from hurting, keep your bottle as full as possible, pausing to refill it often. This will reduce the amount of pressure you need to put on the bottle to create your design. You may also want to avoid the thinnest gauge tips, as they clog easily and are hard to unclog!
Cones are usually made from cellophane or Mylar, rolled into a cone shape. They are much easier on the hand as they don’t take as much pressure to squeeze. You control the thickness of the line two ways. By cutting the tip to the desired diameter and by applying lighter or heavier pressure. There can be a learning curve when it comes to getting used to them, but in the long run many artists prefer them for ease of use and versatility.