The CBSE Maths Sample Paper  Class 12 for 2019 Boards has been summarised here.
We will see how many questions are there, how many marks per chapter and some tips for your board exams.
Sections
There are total 4 sections, marks per section and number of questions is given below
Section  How many marks?  Number of Questions  Total Marks 
Section A  1 marks each  4  1 × 4 = 4 
Section B  2 marks each  8  2 × 8 = 16 
Section C  4 marks each  11  4 × 11 = 44 
Section D  6 marks each  6  6 × 6 = 36 
Total  100 
Marks per Chapter
According to CBSE Syllabus , the marks per unit is like this
Unit  Topic  Chapters of NCERT  Marks 
I.  Relations and Functions  Chapter 1, 2  10 
II.  Algebra  Chapter 3, 4  13 
III.  Calculus  Chapter 5, 6, 7, 8, 9  44 
IV.  Vectors and 3D Geometry  Chapter 10, 11  17 
V.  Linear Programming  Chapter 12  6 
VI.  Probability  Chapter 13  10 
Total  100 
In this sample paper, lets see how many questions of which chapter are asked
Chapter  1 Mark Questions  2 Mark Questions  4 Mark Questions  6 Mark Questions  Total Marks 
Chapter 1  Relations and Functions  1  1 OR Question  6  
Chapter 2  Inverse Trigonometry  1  4  
Chapter 3  Matrices  1  1 OR Question  8  
Chapter 4  Determinants  1  1  5  
Chapter 5  Continuity and Differentiability  1  1 OR Question  5  
Chapter 6  Application of Derivatives  1  1  10  
Chapter 7  Integration  2 (in which 1 OR question)  2 (1 Definite Integral, 1 Indefinite Integral)  12  
Chapter 8  Application of Integration (Area)  1 OR Question  6  
Chapter 9  Differential Equations  1  1  2 (in which 1 OR Question)  11  
Chapter 10  Vector Algebra  1 OR Question  1  6  
Chapter 11  3D Geometry  1 OR Question  1  1 OR Question  11  
Chapter 12  Linear Programming  1  6  
Chapter 13  Probability  2 (in which 1 OR Question)  1  10  
Total  100 
There are total 29 questions, with 1 + 3 + 3 + 3 = 10 OR questions
Observations from the paper

NCERT Questions are very important  3 Questions out of 30 have come straight from NCERT.

1 Question of 6 marks will come of Linear Programming (Chapter 12)

In linear programming question, correct graph is of 2 marks

1 Question of 6 marks will come of Chapter 8 Areas

In Area question, correct figure has 1 marks

1 Question of 6 or 4 marks will come of Limit as a sum or Definite Integral

1 Question of 6 or 4 marks will come for finding Inverse of Matrix (by Properties of Matrix or Determinant)

1 mark question has no step marking. If answer is wrong, 1 mark is cut.

Chapter 13 Probability Random Variable question or Bayes Theorem Question will come of 4 marks or 6 marks

There is formula to find Area of parallelogram when diagonals are given
 And there is a formula for Determinant of A ^{ 1 } i..e A ^{ 1 } 
Tips for CBSE Boards 2019

Revise the chapters from the Concept wise. Check out the video below

In the exam, start doing the 1 mark, and 2 marks questions first. Then do the questions which you think you can do first.
Example  If you know how to solve Linear Programming Question, do that first.

Keep in mind the step marking in the exam. Don't miss any steps! There are marks for correct figure, and correct formula

Do this year's
Sample Paper
atleast

Questions from Supplementary Exercise can come. This year's sample paper had a question of 3 vectors coplanar (which is in Supplementary Exercise of Chapter 10 Vector Algebra)

You should know the basic Concept of each topic of all the chapters. This is very important because most question are conceptual. (You can check concepts by clicking a topic in Concept Wise)
 Keep 2 spare pens, pencil and a scale (ruler) in your geometry box
Have anything else? Comment below to tell me.
All the best!