How to solve nonograms

Rules are very simple. The numbers in row and column clues tell how many black squares are in each row/column and how they are ordered. If clues have same color and shape, the blocks are always separated by at least one white square. In case clues have different color or shape, the blocks can be bounded together.
And that's all.
E.g., clues:

2

1

valid combinations

2

1

2

1

2

1

E.g., clues:

2

1

valid combinations

2

1

2

1

2

1

2

1

2

1

E.g., clues:

2

1

valid combinations

2

1

2

1

2

1

2

1

2

1

Clues:

3

Place block on the leftmost position:
and on the rightmost position:
Overlapped squares must be black:

It can be applied on rows with more clues:

2

2

Clues:

2

2

The middle square must be white, because is out of range of any blocks:

This technique is very often used at the border. Clues

3

The first (and last) two squares must be white, because are out of range:

Clues:

2

2

The middle square must be white, because the gap is too small to fit any clue:

Clues:

3

In case the black square is closer to the border than the length of first clue, the first clue will spread that black square. The 3rd square must be black:

Clues:

2

2

The middle square must be white, because the black square would produce 3 black squares and it does not match any clue:

Clues:

2

3

2

The middle square must be black, otherwise white square would produce 4 blocks and the row has only 3 clues.

Find out by yourself.