As you get more and more into the world of making electronics, you may find that you need to solder components onto circuit boards using a reflow soldering process (short video of it below). Though this may seem like an exotic method used by large manufactures, the good news is that some of these machines are quite accessible. In fact, a quick search will likely pull up reflow ovens for well under $1000.
On the other hand, the process of heating up the solder paste in a controlled manner isn’t really that exotic of an endeavor, and, if you happen to have an old toaster oven lying around, you can convert this into a reflow device. You can see an example of how this can be done on this instructables page, though I woudn’t be too keen on using it for toast afterwards.
If you’d like a little help getting started on your toaster oven project, or if you’d like a nice color interface, you might check out the X-toaster toaster oven reflow controller kit. The device allows you to enhance your oven for general use without internally modifying the oven, and it can be programmed without using a PC. More information on how the device can be set up is found on their website.