Coins are an absolute necessity throughout the game. You will need LOTS of coins
First and foremost, the more often you go into your parks and collect coins, and more profitable your parks will be. This is because different creatures generate income for different amounts of time. Some only generate coins for an hour or two others are three or four hours. Others generate coins for a full 24 hours. Whether it be 1, 2 or 24 hours, after that time has passed, they are no longer generating income. Collecting from your parks frequently will have a big impact on how many coins you have. Lets consider the 4 dinos listed directly below....
If we collected from these 4 dinos just once in a 24 hour period, we would get 76,789 coins
If we collected from them twice in a 24 hour period, we would get 131,114 coins
Collecting 3 times in 24 hours = 185,439 coins
Collecting 4 times in 24 hours = 239,764 coins
Collecting 5 times in 24 hours = 294,065 coins
Buildings can also be very profitable. Placing a large amount of high paying buildings is a strategy that some people use. You can increase the multiplier on buildings just like you can with your dinos. Or you can just place numerous buildings. For example, if you place 30 family lodges in your Jurassic Park, they would generate 30000 coins every 2 hours. But don't forget to collect from them every 2 hours or else they'll stop generating income.
Spamming your parks with lots of buildings can help increase your profits
Park decorations will increase the multiplier (or bonus) on your dinos and buildings. At lower levels it can be difficult to use decorations to help generate income. At lower levels the decorations available to you and the decorations you can afford simply don't create a noticeable increase in how many coins you park generates. So for lower level players I suggest buying only the decorations needed to complete missions and focusing more on the battle arena as a source of income. Once you begin stockpiling coins, you can start placing decorations that are more worthwhile. When buying decorations, be sure to pay close attention to both the multiplier and the coverage area for the decorations your buying. With proper planning, you can get 100%+ multipliers on your dinos very easily. The t-rex can have up to an 880% multiplier... can you figure out how? Hint: it costs dino bucks. See Answer
Harbors & Dino Food
Your harbors are very important to you and your park. Fully evolving numerous dinos will require a huge amount of food. Big animals have big appetites. Running out of food will slow the evolution of your creatures. I STRONGLY recommend that you level up your harbors (level 8 is max) as soon as possible and if at all possible, keep them running 24 hours day. Even if you don't need the food at that moment, keep the harbors running and stockpile. Food can also be collected by spamming the battle arena. Doing this can earn you even more food and will most definitely aid you in keeping your dino food supply above zero.
◇ For lower level players, obtaining dino bucks can be difficult. Watching videos is an easy way to start getting bucks in your inventory. You can get anywhere from 2 or 3 upto around 15 bucks per day. This option is not available on all platforms.
◇ Earning and stockpiling dino bucks becomes easier to do once your able to play in and win all star tournaments. It takes some dedication, but playing in the 120 tournaments daily is the best way to start stockpiling dino bucks. 120 - 30 (entry fee) = 90 dino bucks per win. If you play in and win 1 jurassic, 1 aquatic and 1 glacier tournament with a 120 buck prize per day, that adds up to a profit of 270 dino bucks. During DNA rescue events the all star tournament prize is 80 bucks with a 20 buck entry fee. 3 tournament wins in 1 day during a DNA rescue event will profit you 180 dino bucks.
◇ You can further increase your net profit of dino bucks by playing (AND winning) more tournaments each day. If you play and win three 120 tournaments and two 60 tournaments per day, the net profit will be 360 dino bucks. The number of tournaments you can participate in each day will vary depending on what dinos you have and their level of evolution. With a full arsenal of maxed out gold level creatures such as mine, you can play in 5 tournaments per day (1 Jurassic, 2 Aquatic & 2 Glacier) without buying back any creatures.