Making it stick
One of the biggest issues with 3D printing is getting your prints to stick to the build plate. When a print doesn't stick well, often the print job will curl or fail to print correctly. Here are some methods I've used to get things to work better. Most of these methods I use with the Flashforge Finder, but they can be "transferred" to other printers.
For me, this is the best method for making prints stick to the print bed. In fact, the Flashforge Finder 2 includes a glue stick in the package. I have found that simply rubbing the glue stick on the build plate, creating a thin layer of glue will suffice. Many will say that you need to clean off the glue in between prints. I've found that not to be the case. I will often print several jobs before adding more glue. Find what works best for you.
After a while, it's necessary to clean off the glue and start anew. I often use alcohol wipes and/or Goo Gone to get the glue off. You can also wash the build plate in hot water. Once the glue is off, dry the build plate completely and begin with a new layer of glue.
Frog tape is also a very reliable method for making prints stick, regardless of the printer. Note that I've specified the "Frog Tape" brand. Blue painter's tape (good brands like 3M) works as well, but Frog Tape is far and away the best tape for this task. The tape needs to be prepared with pre-moistened alcohol lens wipes or a lint-free cloth moistened with denatured alcohol. This will clean the tape and give you a better surface for adhesion.
Blue Painter's Tape
As I mentioned above, blue painter's tape can be used as well. I've found that some of the cheaper brands simply don't stick well enough to work. Use a good brand like 3M.
One last one....
On my Makerbot Replicator 2, I've discovered a great method for making print jobs stick. After viewing a youtube video suggesting the idea, I tried the "scuffed" build plate method. Using a piece of sand paper, I scuffed the frosted surface (one side) of the Makerbot acrylic build plate. Don't go crazy, but do make the surface mildly rough. I used 60 - 80 grit sandpaper. You can use finer sandpaper or steel wool if it ends up too rough. No tape or glue necessary. Prints stick and release nicely.