When your print doesn't stick to the bed properly, the most common suspect would be an uneven bed. Even If you have recently calibrated it, the bed can become uneven at any time. Please refer to this guide to level the print bed on your Select Mini 3D printer.
3D printing software offers some adjustment for your Z-axis. Unfortunately, Cura does not come default with this setting. You can adjust this by editing G-code Z-axis start points or by installing a plugin such as XYZ Shift. With the plugin, you can adjust the start Z position to start closer or further from the bed if needed.
The most crucial part of a print is the first layer. If the first layer does not come down clean and even, it lays a bad foundation for the rest of the print. We recommend slowing down your first layer speed to at least half of your normal printing speed. In Cura, you can change these settings under the Advance tab and the Speed category.
Different bed material can play a role in how well the first layer of a print sticks. The best option for your printer bed would be blue painters tape. If this tape does not allow the print to stick there are a few tricks to help. The first easiest option would be keeping a can of hairspray near the printer. Right before your print starts, you can put a light dusting of hair spray on the bed. The small amount of hairspray will allow the filament to adhere to the bed better. Another option would be using a glue stick; this is more commonly used if you are using a glass bed but it also works with painters tape. You would only use the glue stick in the small area that the print would actually be sitting.
Many software options like Cura would allow you to change when and how high the fan settings are set to. In Cura, this is set under the Expert tab on the top status bar. Once in expert settings, you will see an option under the Cooling category for when the fan will be at full speed. If your print is lifting and not sticking, try raising this number.
All printing software offers two options to help prints stick; either a raft or a brim. A raft will be used for the print to sit on and allows for some room of error in printing. It will be a structure that the print sits on as well as go a bit further around the perimeter. A brim would only sit outside the perimeter of the build and would help the edges of the print stay adhered to the bed.