GIMP has a "toolbox" to quickly perform basic tasks. Toolbox is customizable, this means that you can add / demove any tool you want. To select tools for doing something, go to the "Tools" menu, and select any tool you want. To put the tool on the panel go to "Edit > Preferences > Toolbox".
But it can only be edited in a linear way, that is, while sorting it in the "options" there's no way to see where tools will finally appear on the grid. Even though the program's layout updates instantly. They push each other around. There's no way to align tools to right or other corners, or each other.
If the user later shifts the width of the toolbox' panel (to optimize space on screen), the grid gets misaligned, so there's a way to accomodate only 1 layout. If leaving a not evenly divisible quantity of tools, the lowest-right corner can't be utilized.
For that matter, it may be useful to make a screenshot of the toolbox with having activated all the needed tools, and lay out the grid in an easy raster program like Paint or GIMP itself, to make the surface look the needed way. Then start moving them in Preferences accordingly. Remember that tools go from the up-left corner, rightwise then down.
By default not all tools are shown - for example GEGL operation and colour tools are omitted. All tools can also be accessed by opening the "Tools" menu. To switch the window to toolbox, you can use Ctrl + B. Shortcuts written here are the default values - you can change them any time in "Edit > Keyboard Shortcuts" or "Edit > Preferences > Keyboard Shortcuts".
More sophisticated tools are not in the toolbox, but next to the Tools, in the Filters menu.
These tools are available by default in toolbox.
|Rectangle||R||Select square or rectangular regions (axis-aligned).|
|Ellipse||E||Select circular or horizontal / vertical elliptic regions. Notice that there's no ellipse drawing tool as such, only selecting.|
|Free (Lasso)||F||Free-form selecting.|
|Fuzzy (Magic Wand)||U||Select by colour in continuous regions.|
|By Colour||Shift + O||Select by colour without limit to continuency.|
|Scissors||I||Create paths to select shapes.|
|Foreground||(none)||Select a region containing foreground objects.|
|Bucket Fill||Shift + B||Fills areas with a colour or pattern.|
|Blend (Gradient)||L||Fill an area with a gradient.|
|Pencil||N||Draw exact pixel-edged lines; that is, not anti-aliased.|
|Paintbrush||P||Paints soft- or fuzzy-edged lines; that is, the pixels are anti-aliased and/or feathered.|
|Eraser||Shift + E||Erase pixels from a layer.|
|Airbrush||A||Paint tool with a softer pressure.|
|Ink||K||Paint anti-aliased with a simulation of a nib.|
|Clone||C||Copy pixels from one part of an image to another.|
|Heal||H||Heal image irregularities.|
|Perspective Clone||(none)||Clone from an image source after applying perspective transformation.|
|Convolve (Blur/Sharpen)||Shift + U||Blur or sharpen an image.|
|Smudge||S||Mix adjacent pixels; with a direction.|
|Dodge/Burn||Shift + D||Lighten or darken an image's shadows, mid tones or highlights.|
|Move||M||Move selections and layers.|
|Align||Q||Align or arrange layers and/or other objects.|
|Crop||Shift + C||Crop or clip all the image.|
|Rotate||Shift + R||Rotate the active layer, selection or path.|
|Scale||Shift + T||Scale the active layer, selection or path.|
|Shear||Shift + S||Tilt part of the image to some direction.|
|Perspective||Shift + P||Imitate 3-dimensional shift of an image.|
|Flip||Shift + F||Flip selections and layers.|
|Path||B||Allows selecting and modifying paths.|
|Colour Picker||O||Select the colour from anywhere in open images for further drawing.|
|Magnify (Zoom)||Z||Alter the zoom level in the program.|
|Measure||Shift + M||Shows distances and angles.|
|Text||T||Place text layers into your image.|
There are also some other tools, hidden by default. These tools are accessed from the "Tools" menu, or by showing them in toolbox.