Goals should be SMART!

S -> Specific
M -> Measurable
A -> Attainable
R -> Relevant (Risky and Rewarding)
T -> Time-Bound

Specific: 

Goals should be specific and unambiguous. Describe and quantify your goals as clearly as possible.
A clear, quantifiable and unambiguous goal will be necessary when determining the success or failure of the project/task.
  
Measurable:

Goals should be measurable. The measurability of your goal is derived from and dependent on how clear and specific the goal is.
Goals which are not specific and measurable has no basis to provide guidance and direction to the efforts and activities involved in the project/task.
Any goals which are not measurable (and specific) cannot provide the baseline to determine whether the project is successful or not. 

Attainable, Relevant, & Time-Bound:

Goals should be attainable, relevant and time-bound. Goals which are not attainable and relevant (risky and rewarding) has no fundamental basis to demand
from you your engagement in the project. The project/task would simply be a waste of your Time, Effort and Resources if the goals are not attainable and relevant to begin with.
Goals should be time-bound (time-specific or time-limited). Set a time frame or end point for the goal. Without a time frame, your commitment to the goal would be half-hearted and sloppy. Without a time limit, there is no urgency to start taking action now. The time frame will also prompt you to manage and look into the availability of the required tools and resources to be able to achieve your goal.

Again, make SMART Goals!

Very IMPORTANT Goal Setting Requirement:

When you already have in mind your SMART Goals, write them down and make them visible to you each day. Having the goals written down and visible to you each day will be a powerful reminder to keep your daily efforts and tasks directed towards achieving your longer-term goals.

Goal Setting Quotes:

Below are some very helpful motivational quotes which summarizes the guidelines discussed on goal settings above: 

"If you don't have the time to write down your goals and action plans, where will you find the time to achieve your goals?" - C. Pulsifer

Our plans miscarry because they have no aim. When a man does not know what harbor he is making for, no wind is the right wind. - Seneca

A dream is just a dream. A goal is a dream with a plan and a deadline. - Harvey Mackay

The trouble with not having a goal is that you can spend your life running up and down the field and never score. - Bill Copeland

Progress has little to do with speed, but much to do with direction. - Author Unknown

In life, as in football, you won’t go far unless you know where the goalposts are. - Arnold H. Glasgow