When it comes to Garry's Mod aside from building, Movement is also an important thing in the game and there is many types of movement in Garry's Mod, So this guide is mainly to demonstrate a very well known movement type in both Half Life 2 and Garry's Mod.

Accelerated BackHooping or ABH if you are in a rush is an extremely useful movement strategy no matter if its for combat or noclip is just too slow for you.
How To Accelerate BackHop: Hold W and Shift, Jump then turn your mouse a 180 Degree angle (or just turn around) Then let go of W and Shift and hold Control and Time Your jumps with Spacebar

Accelerated Side Hop, or ASH, is a slightly harder method to perform, yet offers the player the advantage of being able to face slightly forwards. To execute this, start an ABH but instead of turning around in the air, adjust your view slightly to the left (or right) and hold S and D (or S and A) to gain speed.

Similar to the 2 previous accelerated movements, Accelerated FrontHopping is an extremely difficult method but rewarding method of movement in Garry's Mod and Half Life 2.
How To Accelerate Fronthop: Hold W and Shift, Jump then hold Control and press S and Spacebar at the same time which in return makes you Accelerate FrontHop.

No matter which of the following speedrun methods you prefer at the end of the day we can all agree that these hopping techniques are easily the most effective way to get from one place to another on the map, so i dearly hope that at the end of the day you may have learned a thing or two from this guide.