In or near real-time monitoring of fluids can take place using an opticoanalytical device that is configured for monitoring the fluid. Fluids can be monitored prior to or during their introduction into a subterranean formation using the opticoanalytical devices. Produced fluids from a subterranean formation can be monitored in a like manner. The methods can comprise providing a treatment fluid comprising a base fluid and at least one additional component; introducing the treatment fluid into a subterranean formation; allowing the treatment fluid to perform a treatment operation in the subterranean formation; and monitoring a characteristic of the treatment fluid or a formation fluid using at least a first opticoanalytical device within the subterranean formation, during a flow back of the treatment fluid produced from the subterranean formation, or both.